Translumenally implantable heart valve with formed in place support

ABSTRACT

A cardiovascular prosthetic valve, the valve comprising an inflatable cuff comprising at least one inflatable channel that forms, at least in part, an inflatable structure, and a valve coupled to the inflatable cuff, the valve configured to permit flow in a first axial direction and to inhibit flow in a second axial direction opposite to the first axial direction, the valve comprising a plurality of tissue supports that extend generally in the axial direction and that are flexible and/or movable throughout a range in a radial direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/976,671, filed Dec. 22, 2010, which is a continuation of U.S. patentapplication Ser. No. 12/197,172, filed Aug. 22, 2008, which claimspriority to U.S. Provisional Application No. 60/957,691, filed Aug. 23,2007, all of these applications are hereby incorporated by referenceherein in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to medical methods and devices, and, inparticular, to methods and devices for percutaneously implanting astentless valve having a formed in place support structure.

Description of the Related Art

According to recent estimates, more than 79,000 patients are diagnosedwith aortic and mitral valve disease in U.S. hospitals each year. Morethan 49,000 mitral valve or aortic valve replacement procedures areperformed annually in the U.S., along with a significant number of heartvalve repair procedures.

The circulatory system is a closed loop bed of arterial and venousvessels supplying oxygen and nutrients to the body extremities throughcapillary beds. The driver of the system is the heart providing correctpressures to the circulatory system and regulating flow volumes as thebody demands. Deoxygenated blood enters heart first through the rightatrium and is allowed to the right ventricle through the tricuspidvalve. Once in the right ventricle, the heart delivers this bloodthrough the pulmonary valve and to the lungs for a gaseous exchange ofoxygen. The circulatory pressures carry this blood back to the heart viathe pulmonary veins and into the left atrium. Filling of the left atriumoccurs as the mitral valve opens allowing blood to be drawn into theleft ventricle for expulsion through the aortic valve and on to the bodyextremities. When the heart fails to continuously produce normal flowand pressures, a disease commonly referred to as heart failure occurs.

Heart failure simply defined is the inability for the heart to produceoutput sufficient to demand. Mechanical complications of heart failureinclude free-wall rupture, septal-rupture, papillary rupture ordysfunction aortic insufficiency and tamponade. Mitral, aortic orpulmonary valve disorders lead to a host of other conditions andcomplications exacerbating heart failure further. Other disordersinclude coronary disease, hypertension, and a diverse group of musclediseases referred to as cardiomyopothies. Because of this syndromeestablishes a number of cycles, heart failure begets more heart failure.

Heart failure as defined by the New York Heart Association in afunctional classification.

-   -   I. Patients with cardiac disease but without resulting        limitations of physical activity. Ordinary physical activity        does not cause undue fatigue, palpitation, dyspnea, or anginal        pain.    -   II. Patient with cardiac disease resulting in slight limitation        of physical activity. These patients are comfortable at rest.        Ordinary physical activity results in fatigue, palpitation,        dyspnea, or anginal pain.    -   III. Patients with cardiac disease resulting in marked        limitation of physical activity. These patients are comfortable        at rest. Less than ordinary physical activity causes fatigue        palpitation, dyspnea, or anginal pain.    -   IV. Patients with cardiac disease resulting in inability to        carry on any physical activity without discomfort. Symptoms of        cardiac insufficiency or of the anginal syndrome may be present        even at rest. If any physical activity is undertaken, discomfort        is increased.

There are many styles of mechanical valves that utilize both polymer andmetallic materials. These include single leaflet, double leaflet, balland cage style, slit-type and emulated polymer tricuspid valves. Thoughmany forms of valves exist, the function of the valve is to control flowthrough a conduit or chamber. Each style will be best suited to theapplication or location in the body it was designed for.

Bioprosthetic heart valves comprise valve leaflets formed of flexiblebiological material. Bioprosthetic valves or components from humandonors are referred to as homografts and xenografts are from non-humananimal donors. These valves as a group are known as tissue valves. Thistissue may include donor valve leaflets or other biological materialssuch as bovine pericardium. The leaflets are sewn into place and to eachother to create a new valve structure. This structure may be attached toa second structure such as a stent or cage or other prosthesis forimplantation to the body conduit.

Implantation of valves into the body has been accomplished by a surgicalprocedure and has been attempted via percutaneous method such as acatheterization or delivery mechanism utilizing the vasculaturepathways. Surgical implantation of valves to replace or repair existingvalves structures include the four major heart valves (tricuspid,pulmonary, mitral, aortic) and some venous valves in the lowerextremities for the treatment of chronic venous insufficiency.Implantation includes the sewing of a new valve to the existing tissuestructure for securement. Access to these sites generally include athoracotomy or a sternotomy for the patient and include a great deal ofrecovery time. An open-heart procedure can include placing the patienton heart bypass to continue blood flow to vital organs such as the brainduring the surgery. The bypass pump will continue to oxygenate and pumpblood to the body's extremities while the heart is stopped and the valveis replaced. The valve may replace in whole or repair defects in thepatient's current native valve. The device may be implanted in a conduitor other structure such as the heart proper or supporting tissuesurrounding the heart. Attachments methods may include suturing, hooksor barbs, interference mechanical methods or an adhesion median betweenthe implant and tissue.

Although valve repair and replacement can successfully treat manypatients with valvular insufficiency, techniques currently in use areattended by significant morbidity and mortality. Most valve repair andreplacement procedures require a thoracotomy, usually in the form of amedian sternotomy, to gain access into the patient's thoracic cavity. Asaw or other cutting instrument is used to cut the sternumlongitudinally, allowing the two opposing halves of the anterior orventral portion of the rib cage to be spread apart. A large opening intothe thoracic cavity is thus created, through which the surgical team maydirectly visualize and operate upon the heart and other thoraciccontents. Alternatively, a thoracotomy may be performed on a lateralside of the chest, wherein a large incision is made generally parallelto the ribs, and the ribs are spread apart and/or removed in the regionof the incision to create a large enough opening to facilitate thesurgery.

Surgical intervention within the heart generally requires isolation ofthe heart and coronary blood vessels from the remainder of the arterialsystem, and arrest of cardiac function. Usually, the heart is isolatedfrom the arterial system by introducing an external aortic cross-clampthrough a sternotomy and applying it to the aorta to occlude the aorticlumen between the brachiocephalic artery and the coronary ostia.Cardioplegic fluid is then injected into the coronary arteries, eitherdirectly into the coronary ostia or through a puncture in the ascendingaorta, to arrest cardiac function. The patient is placed onextracorporeal cardiopulmonary bypass to maintain peripheral circulationof oxygenated blood.

Since surgical techniques are highly invasive and in the instance of aheart valve, the patient must be put on bypass during the operation, theneed for a less invasive method of heart valve replacement has long beenrecognized. At least as early as 1972, the basic concept of suturing atissue aortic valve to an expandable cylindrical “fixation sleeve” orstent was disclosed. See U.S. Pat. No. 3,657,744 to Ersek. Other earlyefforts were disclosed in U.S. Pat. No. 3,671,979 to Moulopoulos andU.S. Pat. No. 4,056,854 to Boretos, relating to prosthetic valvescarried by an expandable valve support delivered via catheter for remoteplacement. More recent iterations of the same basic concept weredisclosed, for example, in patents such as U.S. Pat. Nos. 5,411,552,5,957,949, 6,168,614, and 6,582,462 to Anderson, et al., which relategenerally to tissue valves carried by expandable metallic stent supportstructures which are crimped to a delivery balloon for later expansionat the implantation site.

In each of the foregoing systems, the tissue or artificial valve isfirst attached to a preassembled, complete support structure (some formof a stent) and then translumenally advanced along with the supportstructure to an implantation site. The support structure is thenforceably enlarged or allowed to self expand without any change in itsrigidity or composition, thereby securing the valve at the site.

Despite the many years of effort, and enormous investment ofentrepreneurial talent and money, no stent based heart valve system hasyet received regulatory approval, and a variety of difficulties remain.For example, stent based systems have a fixed rigidity even in thecollapsed configuration, and have inherent difficulties relating topartial deployment, temporary deployment, removal and navigation.

Thus, a need remains for improvements over the basic concept of a stentbased prosthetic valve. As disclosed herein a variety of significantadvantages may be achieved by eliminating the stent and advancing thevalve to the site without a support structure. Only later, the supportstructure is created in situ such as by inflating one or more inflatablechambers to impart rigidity to an otherwise highly flexible andfunctionless subcomponent.

SUMMARY OF THE INVENTION

In accordance with one aspect of present invention, there is provided aninflatable or formed in place support for a translumenally implantableheart valve, in which a plurality of tissue supports are flexible and/ormovable throughout a range in a radial direction. As used herein, aradial direction is a direction which is transverse to the longitudinalaxis of the flow path through the valve.

Further features and advantages of the present invention will becomeapparent from the detailed description of preferred embodiments whichfollows, when considered together with the attached drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional schematic view of a heart and its majorblood vessels.

FIG. 2 is a partial cut-away view a left ventricle and aortic with anprosthetic aortic valve implant according to one embodiment of thepresent invention positioned therein.

FIG. 2A is a side view of the implant of FIG. 2 positioned across anative aortic valve.

FIG. 2B is a schematic top illustration of a modified embodiment of animplant positioned across the aortic valve.

FIG. 2C is a schematic cross-sectional view of a modified embodiment ofan implant.

FIG. 2D is a side cross-sectional view of another embodiment of animplant positioned at the aortic valve.

FIGS. 2E and 2F are side and bottom views of another embodiment of animplant.

FIGS. 2G and 2H are side and bottom views of another embodiment of animplant.

FIG. 3A is a front perspective view of the implant of FIG. 2.

FIG. 3B is a cross-sectional side view of the implant of FIG. 3A.

FIG. 3C is an enlarged cross-sectional view of a lower portion of FIG.3B.

FIG. 3D is a front perspective view of an inflatable support structureof the implant of FIG. 3A.

FIG. 4 is a front perspective view of a modified embodiment of animplant.

FIG. 5A is a front perspective view of another modified embodiment of animplant.

FIG. 5B is cross-sectional view taken through line 5B-5B of FIG. 5A

FIG. 6 is a front perspective view of another embodiment of an implant.

FIG. 7A is a front perspective view of another embodiment of an implant.

FIG. 7B is cross-sectional view taken through line 7B-7B of FIG. 7A.

FIG. 8A is a front perspective view of another embodiment of an implant.

FIG. 8B is cross-sectional view taken through line 8B-8B of FIG. 8A

FIG. 9A is a front perspective view of another embodiment of an implant.

FIG. 9B is cross-sectional view taken through line 9B-9B of FIG. 9A.

FIG. 10 is an embodiment of a cross-section of an inflation channel.

FIG. 11 is a front perspective view of another embodiment of an implant.

FIG. 12 is a cross-sectional side view of the implant of FIG. 11positioned across an aortic valve.

FIGS. 13A-D are front perspective views of three modified embodiments ofa valve implant.

FIG. 14 is a side perspective view of a method of forming a lumen in anvalve implant.

FIG. 15 is a top perspective view of a method of attaching a valve to avalve implant.

FIG. 16A-B are front perspective views of two modified embodiments of avalve implant.

FIG. 17A-B are front perspective views of two modified embodiments of anon-inflatable valve implant.

FIGS. 18A-C are time sequence steps of deploying a non-inflatable valveimplant.

FIG. 19 is a side view of an un-deployed non-inflatable valve implant.

FIG. 19A is a cross-sectional view taken at line 19A-19A of FIG. 19.

FIG. 19B is a side view of another embodiment of un-deployednon-inflatable valve implant.

FIG. 19C is a top view of the valve implant of FIG. 19B in a deployedstate.

FIG. 20 is side view of another embodiment of an un-deployednon-inflatable valve.

FIG. 20A is a cross-sectional view taken at line 20A-20A of FIG. 20.

FIGS. 21A-B are time sequenced steps of deploying a non-inflatable valveimplant

FIGS. 22A-B illustrate the deployment of a modified embodiment of anon-inflatable valve implant.

FIG. 23 are top views of a modified embodiment of a non-inflatable valveimplant in an expanded and compressed configuration.

FIGS. 24A-B are side perspective views of a modified embodiment of anon-inflatable valve implant in an expanded and compressedconfiguration.

FIGS. 25A-C are side perspective views of a modified embodiment of anon-inflatable valve implant in an expanded, compressed and assembledconfiguration.

FIG. 25D is a side perspective view of another embodiment of anon-inflatable valve implant.

FIGS. 25E-F are side perspective views of another embodiment of anon-inflatable valve implant.

FIG. 26 is a side perspective view of an anchor for an implant valve.

FIGS. 27A-C are time sequenced steps of securing an implant to the aortawith a staple or clip.

FIGS. 27D-E are side views of another embodiment of securing an implantto the aorta with a staple or clip.

FIG. 28 is a side perspective view of another embodiment of an anchorfor an implant valve.

FIG. 28A is a side perspective view of another embodiment of an anchorfor an implant valve.

FIG. 29 is a side perspective view of another embodiment of an anchorfor an implant valve.

FIG. 30 is a side perspective view of another embodiment of an anchorfor an implant valve.

FIG. 30A is a side perspective view of another embodiment of an anchorfor an implant valve in a deployed and un-deployed configuration.

FIG. 31 is a side perspective view of another embodiment of an anchorfor an implant valve in a deployed and un-deployed configuration.

FIG. 32 is a top and side views of another embodiment of an anchor foran implant valve in a deployed and un-deployed configuration.

FIG. 32A is a side perspective view of another embodiment of an anchorfor an implant valve.

FIG. 33 is a side perspective view of another embodiment of an anchorfor an implant valve.

FIG. 34 is a side view of a deployment catheter.

FIG. 35 is a side view of the deployment catheter of FIG. 34 with anouter sheath partially withdrawn.

FIGS. 35A and 35B are side views of a modified embodiment of the distalend of the deployment catheter of FIG. 35.

FIG. 36 is a side view of the deployment catheter of FIG. 35 with anouter sheath partially withdrawn and the implant deployed.

FIG. 36A is an enlarged view of the distal portion of the deploymentcatheter shown in FIG. 36.

FIG. 36B is a cross-sectional view taken through line 36B-36B of FIG.36A.

FIG. 37 is a side view of the deployment catheter of FIG. 35 with anouter sheath partially withdrawn and the implant deployed and detached.

FIG. 37A is a side view of another embodiment of a deployment catheter.

FIGS. 38A-C are schematic partial cross-sectional views of a modifiedembodiment of a deployment catheter with the implant in a stored,partially deployed and deployed position.

FIGS. 39A-D are cross-sectional side views of four embodiments of asealing mechanism.

FIGS. 40A-B are cross-sectional side views of a sealing and connectionmechanism in a connected and disconnected confirmation.

FIG. 41 is a cross-sectional side view of a sealing and connectionmechanism.

FIG. 42 is cross-sectional side view of a sealing and connectionmechanism in a connected and disconnected confirmation.

FIG. 43 is a cross-sectional side view of a sealing and connectionmechanism.

FIG. 44 is a side perspective view of an embodiment of connecting acontrol wire to a prosthetic valve implant.

FIGS. 45A-C illustrates time sequence steps of partially deploying andpositioning an artificial valve implant.

FIGS. 46A-C illustrates time sequence steps of deploying and withdrawingan artificial valve implant.

FIGS. 47A-E illustrates time sequence steps of deploying, testing andrepositioning an artificial valve implant.

FIG. 48 is a side perspective view of an embodiment of connecting acontrol wire to a prosthetic valve implant.

FIG. 49A is a side view of an embodiment of a control wire withcontrolled flexibility.

FIG. 49B is a side view of another embodiment of a control wire withcontrolled flexibility.

FIG. 49C is a cross-sectional front view of another embodiment of acontrol wire with controlled flexibility in a first position.

FIG. 49D is a cross-sectional front view the control wire of FIG. 49C ina second position.

FIG. 50 is a side view of a distal end of a recapture device.

FIG. 51 is a side view of a distal end of another embodiment of arecapture device.

FIG. 52A is a partial cross-sectional view of the heart and the aortawith a temporary valve positioned therein.

FIG. 52B is a partial cross-sectional view of the heart and the aortawith protection device positioned therein

FIG. 53A is a side view of an embodiment of an excise device.

FIG. 53B is a closer view of a portion of FIG. 53A.

FIG. 54A is a closer view of the distal end of the excise device of FIG.53A.

FIG. 54B is a cross-sectional view taken through line 54B-54B of FIG.53A.

FIG. 54C is a cross-sectional view taken through line 54C-54C of FIG.53A.

FIG. 55A is a cross-sectional view of a distal end of another embodimentof an excise device.

FIG. 55B is a cross-sectional view taken through line 55B-55B of FIG.55A.

FIG. 56A is a side view of a distal end of another embodiment of anexcise device.

FIG. 56B is a cross-sectional view taken through line 56B-56B of FIG.56A.

FIG. 56C is a cross-sectional view taken through line 56C-56C of FIG.56A.

FIG. 56D is a side view of another embodiment of a debulking device.

FIGS. 57A-O are time sequenced steps of an embodiment of a method fordeploying a temporary valve, an excise device and a prosthetic valveimplant.

FIG. 58 is a side perspective view of another embodiment of a valve.

FIG. 59 is a top plan view of the valve of FIG. 58.

FIG. 59A is a partial cross-sectional view of a portion of the valve ofFIG. 58.

FIG. 60 is another top plan view of the valve of FIG. 58.

FIG. 60A is another partial cross-sectional view of a portion of thevalve of FIG. 58.

FIG. 61 is another partial cross-sectional view of a portion of thevalve of FIG. 58.

FIG. 62 is another partial cross-sectional view of a portion of thevalve of FIG. 58.

FIG. 63 is side perspective view of another embodiment of a valve.

FIG. 64 is side perspective view of another embodiment of a valve.

FIG. 64A is side perspective view of another embodiment of a valve.

FIG. 65-68 are cross-sectional and side views of portions of the valveof FIG. 65.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a schematic cross-sectional illustration of the anatomicalstructure and major blood vessels of a heart 10. Deoxygenated blood isdelivered to the right atrium 12 of the heart 10 by the superior andinferior vena cava 14, 16. Blood in the right atrium 12 is allowed intothe right ventricle 18 through the tricuspid valve 20. Once in the rightventricle 18, the heart 10 delivers this blood through the pulmonaryvalve 22 to the pulmonary arteries 24 and to the lungs for a gaseousexchange of oxygen. The circulatory pressures carry this blood back tothe heart via the pulmonary veins 26 and into the left atrium 28.Filling of the left atrium 28 occurs as the mitral valve 30 opensallowing blood to be drawn into the left ventricle 32 for expulsionthrough the aortic valve 34 and on to the body extremities through theaorta 36. When the heart 10 fails to continuously produce normal flowand pressures, a disease commonly referred to as heart failure occurs.

One cause of heart failure is failure or malfunction of one or more ofthe valves of the heart 10. For example, the aortic valve 34 canmalfunction for several reasons. For example, the aortic valve 34 may beabnormal from birth (e.g., bicuspid, calcification, congenital aorticvalve disease), or it could become diseased with age (e.g., acquiredaortic valve disease). In such situations, it can be desirable toreplace the abnormal or diseased valve 34.

FIG. 2 is a schematic illustration of the left ventricle 32, whichdelivers blood to the aorta 36 through the aortic valve 34. The aorta 36comprises (i) the ascending aorta 38, which arises from the leftventricle 32 of the heart 10, (ii) the aortic arch 10, which arches fromthe ascending aorta 38 and (iii) the descending aorta 42 which descendsfrom the aortic arch 40 towards the abdominal aorta (not shown). Alsoshown are the principal branches of the aorta 14, which include theinnomate artery 44 that immediately divides into the right carotidartery (not shown) and the right subclavian artery (not shown), the leftcarotid 46 and the subclavian artery 48.

Inflatable Prosthetic Aortic Valve Implant

With continued reference to FIG. 2, a prosthetic aortic valve implant100 in accordance with an embodiment of the present invention is shownspanning the native abnormal or diseased aortic valve 34, which has beenpartially removed as will be described in more detail below. The implant100 and various modified embodiments thereof will be described in detailbelow. As will be explained in more detail below, the implant 100 ispreferably delivered minimally invasively using an intravasculardelivery catheter 200 or trans apical approach with a trocar.

In the description below, the present invention will be describedprimarily in the context of replacing or repairing an abnormal ordiseased aortic valve 34. However, various features and aspects ofmethods and structures disclosed herein are applicable to replacing orrepairing the mitral 30, pulmonary 22 and/or tricuspid 20 valves of theheart 10 as those of skill in the art will appreciate in light of thedisclosure herein. In addition, those of skill in the art will alsorecognize that various features and aspects of the methods andstructures disclosed herein can be used in other parts of the body thatinclude valves or can benefit from the addition of a valve, such as, forexample, the esophagus, stomach, ureter and/or vesice, biliary ducts,the lymphatic system and in the intestines.

In addition, various components of the implant and its delivery systemwill be described with reference to coordinate system comprising“distal” and “proximal” directions. In this application, distal andproximal directions refer to the deployment system 300, which is used todeliver the implant 100 and advanced through the aorta 36 in a directionopposite to the normal direction of blood through the aorta 36. Thus, ingeneral, distal means closer to the heart while proximal means furtherfrom the heart with respect to the circulatory system.

With reference now to FIGS. 3A-D, the implant 100 of the illustratedembodiment generally comprises an inflatable cuff or body 102, which isconfigured to support a valve 104 (see FIG. 2) that is coupled to thecuff 102. As will be explained in more detail below, the valve 104 isconfigured to move in response to the hemodynamic movement of the bloodpumped by the heart 10 between an “open” configuration where blood canthrow the implant 100 in a first direction (labeled A in FIG. 3B) and a“closed” configuration whereby blood is prevented from back flowingthrough the valve 104 in a second direction B (labeled B in FIG. 3B).

In the illustrated embodiment, the cuff 102 comprises a thin flexibletubular material 106 such as a flexible fabric or thin membrane withlittle dimensional integrity. As will be explained in more detail below,the cuff 102 can be changed preferably, in situ, to a support structureto which other components (e.g., the valve 104) of the implant 100 canbe secured and where tissue ingrowth can occur. Uninflated, the cuff 102is preferably incapable of providing support. In one embodiment, thecuff 102 comprises Dacron, PTFE, ePTFE, TFE or polyester fabric 106 asseen in conventional devices such as surgical stented or stent lessvalves and annuloplasty rings. The fabric 106 thickness may range fromabout 0.002 inches to about 0.020 inches of an inch depending uponmaterial selection and weave. Weave density may also be adjusted from avery tight weave to prevent blood from penetrating through the fabric106 to a looser weave to allow tissue to grow and surround the fabric106 completely. Additional compositions and configurations of the cuff102 will be described in more detail below.

With continued reference to FIGS. 3B-3D, in the illustrated embodiment,the implant 100 includes an inflatable structure 107 that forms one ormore of inflation channels 120, which in illustrated embodiment areformed in part by a pair of distinct balloon rings or toroids 108 a, 108b. The rings 108 a, 108 b in this embodiment are positioned at theproximal and distal ends 126, 128 of the cuff 102. As will be explainedbelow, the rings 108 can be secured to the body 102 in any of a varietyof manners. With reference to FIG. 3C, in the illustrated embodiment,the rings 108 are secured within folds 110 formed at the proximal anddistal ends 126, 128 of the cuff 102. The folds 110, in turn, aresecured by sutures or stitches 112. See FIG. 3C.

The illustrated inflatable structure 107 also includes inflatable struts114, which in the illustrated embodiment are formed from an annularzig-zag pattern having three proximal bends 116 and three distal bends118. As best seen in FIG. 3C, the struts 114 can be secured to the cuff102 within pockets 115 of cuff material by sutures 112. Of course, aswill be explained in more detail, other embodiments other configurationscan be can be used to secure the struts 114 to the fabric 106.

As mentioned above, the inflatable rings 108 and struts 114 form theinflatable structure 107, which, in turn, defines the inflation channels120. The inflation channels 120 receive inflation media 122 to generallyinflate the inflatable structure 107. When inflated, the inflatablerings and struts 108, 114 provide can provide structural support to theinflatable implant 100 and/or help to secure the implant 100 within theheart 10. Uninflated, the implant 100 is a generally thin, flexibleshapeless assembly that is preferably uncapable of support and isadvantageously able to take a small, reduced profile form in which itcan be percutaneously inserted into the body. As will be explained inmore detail below, in modified embodiments, the inflatable structure 107may comprise any of a variety of configurations of inflation channels120 that can be formed from other inflatable members in addition to orin the alternative to the inflatable rings 108 and struts 114 shown inFIGS. 3A and 3B. In addition, the inflatable media 122 and methods forinflating the inflatable structure 107 will be described in more detailbelow.

With particular reference to FIG. 3D, in the illustrated embodiment, theproximal ring 108 a and struts 114 are joined such that the inflationchannel 120 of the proximal ring 108 a is in fluid communication withthe inflation channel 120 of the struts 114. In contrast, the inflationchannel 120 of the distal ring 108 b is not in communication with theinflation channels 120 of the proximal ring 108 a and struts 114. Inthis manner, the inflation channels of the (i) proximal ring 108 a andstruts 115 can be inflated independently from the (ii) distal ring 108b. As will be explained in more detail below, the two groups ofinflation channels 120 are preferably connected to independent fluiddelivery devices to facilitate the independent inflation. It should beappreciated that in modified embodiments the inflatable structure caninclude less (i.e., one common inflation channel) or more independentinflation channels. For example, in one embodiment, the inflationchannels of the proximal ring 108 a, struts 114 and distal ring 108 bcan all be in fluid communication with each other such that they can beinflated from a single inflation device. In another embodiment, theinflation channels of the proximal ring the proximal ring 108 a, struts114 and distal ring 108 b can all be separated and therefore utilizethree inflation devices.

With reference to FIG. 3B, in the illustrated embodiment, the proximalring 108 a has a cross-sectional diameter of about 0.090 inches. Thestruts have a cross-sectional diameter of about 0.060 inches. The distalring 108 b has a cross-sectional diameter of about 0.090 inchesdiameter.

In prior art surgically implanted valves, the valve generally includes arigid inner support structure that is formed from polycarbonate,silicone or titanium wrapped in silicone and Dacron. These surgicalvalves vary in diameter for different patients due to the respectiveimplantation site and orifice size. Generally the largest diameterimplantable is the best choice for the patient. These diameters rangefrom about 16 mm to 30 mm.

As mentioned above, the implant 100 allows the physician to deliver avalve via catheterization in a lower profile and a safer manner thancurrently available. When the implant 100 is delivered to the site via adelivery catheter 300, the implant 100 is a thin, generally shapelessassembly in need of structure and definition. At the implantation site,the inflation media 122 (e.g., a fluid or gas) may be added via acatheter lumen to the inflation channels 120 providing structure anddefinition to the implant 100. The inflation media 122 thereforecomprises part of the support structure for implant 100 after it isinflated. The inflation media 122 that is inserted into the inflationchannels 120 can be pressurized and/or can solidify in situ to providestructure to the implant 100. Additional details and embodiments of theimplant 100, can be found in U.S. Pat. No. 5,554,185 to Block, thedisclosure of which is expressly incorporated in its entirety herein byreference.

With reference to FIG. 2A, in the illustrated embodiment, the implant100 has shape that can be viewed as a tubular member or hyperboloidshape where a waist 124 excludes the native valve or vessel 34 andproximally the proximal end 126 forms a hoop or ring to seal blood flowfrom re-entering the left ventricle 32 Distally, the distal end 128 alsoforms a hoop or ring to seal blood from forward flow through the outflowtrack. Between the two ends 126, 128, the valve 104 is mounted to thebody 102 such that when inflated the implant 100 excludes the nativevalve 34 or extends over the former location of the native valve 34 andreplaces its function. The distal end 128 should have an appropriatesize and shape so that it does not interfere with the proper function ofthe mitral valve, but still secures the valve adequately. For example,there may be a notch, recess or cut out in the distal end 128 of thedevice to prevent mitral valve interference. The proximal end 126 isdesigned to sit in the aortic root. It is preferably shaped in such away that it maintains good apposition with the wall of the aortic root.This prevents the device from migrating back into the ventricle 32. Insome embodiments, the implant 100 is configured such that it does notextend so high that it interferes with the coronary arteries.

Any number of additional inflatable rings or struts may be between theproximal and distal end 126, 128. The distal end 126 of the implant 100is preferably positioned within the left ventrical 34 and can utilizethe aortic root for axial stabilization as it may have a larger diameterthan the aortic lumen. This may lessen the need for hooks, barbs or aninterference fit to the vessel wall. Since the implant 100 may be placedwithout the aid of a dilatation balloon for radial expansion, the aorticvalve 34 and vessel may not have any duration of obstruction and wouldprovide the patient with more comfort and the physician more time toproperly place the device accurately. Since the implant 100 is notutilizing a support member with a single placement option as aplastically deformable or shaped memory metal stent does, the implant100 may be movable and or removable if desired. This could be performedmultiple times until the implant 100 is permanently disconnected fromthe delivery catheter 300 as will be explained in more detail below. Inaddition, the implant 100 can include features, which allow the implant100 to be tested for proper function, sealing and sizing, before thecatheter 300 is disconnected. When the disconnection occurs, a seal atthe device may be required to maintain the fluid within the inflationchannels 120. Devices for providing such a seal will be described inmore detail below.

With reference to FIG. 2B, in a modified embodiment, the shape of thedistal end 128 of the implant 100 can be configured so that the impactto the shape of the mitral valve annulus is minimized. This isparticularly important in the implant 100 extends into or beyond thenative annulus 35 and into the left ventrical 32 as shown in FIG. 2A. Ingeneral, the distal end 128 can be shaped so that the chordae andleaflet tissue from the mitral valve are not impacted or abraded by theimplant 100 during their normal motion. In this manner, the implant 100does not apply or only applies minimal pressure to the major conductionpathways of the heart. Several different embodiment of the valve 100address these issues. In the embodiment shown in FIGS. 2B, 2E and 2F,the distal end 128 of the implant has of a “D” shaped cross sectionwhere the flat side of the “D” is positioned to correspond with themitral valve 22 location. In another embodiment shown in FIG. 2C, thedistal end 128 of the implant 100 has a generally elliptical crosssection, where the minor axis of the ellipse extends generally from themitral valve location to the septal wall. In yet another embodiment, thedistal end 128 of the implant 100 contains feet or enlarged pads,designed to contact the native anatomy at the desired locations. Forexample, the desired locations are just below the annulus in the areason either side of the mitral valve. The feet may be inflatablestructures or separate mechanical structures such as deployable anchorsmay be made from materials such as stainless steel or nitinol. Theseanchors can deployed by the inflation media or a secondary system. FIGS.2G and 2H illustrate an embodiment in which the distal end of the valve100 has a pair of generally opposing flat sides 128 a.

In yet another embodiment of the implant 100, the implant 100 isconfigured such that it does affect the mitral valve 22. In such anembodiment, the distal end 128 of the implant 100 has a protrusion orfeature that pushes on the annulus of the mitral valve 22 from theaortic root or aortic valve annulus. In this way, mitral regurgitationis treated by pushing the anterior leaflet closer 22 a to the posteriorleaflet 22 b and improving the coaptation of the valve. This feature canbe a separate device from the implant 100 and/or it may be actuated by asecondary mechanism, or it may simply be a function of the shape of theimplant 100.

In yet another modified embodiment the implant 100 (see FIG. 2D), for anaortic valve replacement application, the implant 100 uses both the topand bottom of the aortic root for securement. In this case, the axialforce pushing the implant 100 away from the heart 10 is resisted by anormal force from the upper portion of the aortic root. A implant 100designed to be implanted in this configuration can have a differentconfiguration than an implant designed to anchor around the annulus(e.g., the implant 100 shown in FIG. 2A). For example, as shown in FIG.2D, the implant 100 can have a cylindrical or partially spherical shape,where the diameter in the mid portion 124 of the device is larger thanthe diameter at the proximal or distal portions 126, 128. The valve 104can be located in the distal portion 128 of the implant 100 below thecoronary arteries, preferably in a supra-annular position but anintra-annular position would also be possible. Anchors (not shown) canalso be used with a device of this configuration. The anchors preferablyhave a length of 1 to 4 mm and a diameter for 0.010 to 0.020 inches.

With reference back to FIGS. 3A and 3B, the body 102 may be made frommany different materials such as Dacron, TFE, PTFE, ePTFE, woven metalfabrics, braided structures, or other generally accepted implantablematerials. These materials may also be cast, extruded, or seamedtogether using heat, direct or indirect, sintering techniques, laserenergy sources, ultrasound techniques, molding or thermoformingtechnologies. Since the body 102 generally surrounds the inflationlumens 120, which can be formed by separate members (e.g., rings 108),the attachment or encapsulation of these lumens 120 can be in intimatecontact with the body material 106 or a loosely restrained by thesurrounding material 106. These inflation lumens 120 can also be formedalso by sealing the body material 106 to create an integral lumen fromthe body 102 itself. For example, by adding a material such as asilicone layer to a porous material such as Dacron, the fabric 106 canresist fluid penetration or hold pressures if sealed. Materials may alsobe added to the sheet or cylinder material to create a fluid tightbarrier. However, in the illustrated embodiment of FIGS. 3A and 3B, theinflation lumens 120 are formed by balloons 111 (see FIG. 4C), whichform the separate inflation components 108 a, 108 b, 122, which are, inturn, secured to the material 106.

Various shapes of the body 102 may be manufactured to best fitanatomical variations from person to person. As described above, thesemay include a simple cylinder, a hyperboloid, a device with a largerdiameter in its mid portion and a smaller diameter at one or both ends,a funnel type configuration or other conforming shape to nativeanatomies. The shape of the implant 100 is preferably contoured toengage a feature of the native anatomy in such a way as to prevent themigration of the device in a proximal or distal direction. In oneembodiment the feature that the device engages is the aortic root oraortic bulb 34 (see e.g., FIG. 2A), or the sinuses of the coronaryarteries. In another embodiment the feature that the device engages isthe native valve annulus, the native valve or a portion of the nativevalve. In certain embodiments, the feature that the implant 100 engagesto prevent migration has a diametral difference between 1% and 10%. Inanother embodiment the feature that the implant 100 engages to preventmigration the diameter difference is between 5% and 40%. In certainembodiments the diameter difference is defined by the free shape of theimplant 100. In another embodiment the diameter difference preventsmigration in only one direction. In another embodiment. the diameterdifference prevents migration in two directions, for example proximaland distal or retrograde and antigrade. Similar to surgical valves, theimplant 100 will vary in diameter ranging from about 14 mm to about 30mm and have a height ranging from about 10 mm to about 30 mm in theportion of the implant 100 where the leaflets of the valve 104 aremounted. Portions of the implant 100 intended for placement in theaortic root may have larger diameters preferably ranging from about 20to about 45 mm

Different diameters of valves will be required to replace native valvesof various sizes. For different locations in the anatomy, differentlengths of valves or anchoring devices will also be required. Forexample a valve designed to replace the native aortic valve needs tohave a relatively short length because of the location of the coronaryartery ostium (left and right arteries). A valve designed to replace orsupplement a pulmonary valve could have significantly greater lengthbecause the anatomy of the pulmonary artery allows for additionallength.

FIG. 4 illustrates a modified embodiment of the implant 100 in which theimplant 100 includes a distal inflation ring 130 with three commissuralinflatable supports posts 132, which are arranged in a manner similar tothat described above. The valve 104 is supported by the distal inflationring 130 and support posts 132. This shape is similar to a commerciallyavailable valve sold by Edwards Life Science under the trade name ofMagna™ and many other commercially available surgical valves. However,the illustrated embodiment is advantageous because of the inflationchannels (not shown) in the distal inflation ring 130 and supports posts132. As described above, the inflation channels of the inflation ring130 and support posts 132 can be in fluid connection or separated.

Other variations of inflatable valve shapes may include an implant 100in which entire or substantially the entire cuff 102 forms ancylindrical pocket that is filled with fluid creating a cylinder shapewith commissural supports defined by sinusoidal patterns cut from acylindrical portion of the body 102. In such an embodiment, there may bea desire to seam or join the body 102 together at points or areas toprovide passageways for fluid to flow or be restricted. This may alsoallow for wall definition of the body 102 defining a thickness of thecylinder. It may be desired to maintain a thin body wall allowing thelargest area where blood or other fluids may pass through the valve. Thewall thickness of the inflated implant 100 may vary from 0.010 to 0.100of an inch depending upon construction, pressures and materials. Therealso may be a desire to vary the thickness of the cuff wall from distalto proximal or radially. This would allow for other materials such asfixed pericardial tissue or polymer valve materials to be joined to thewall where support is greatest, or allow the maximum effective orificearea in the area of the implant 100 its self. The implant 100 may besealed fluid tight by glue, sewing, heat or other energy sourcesufficient to bond or fuse the body material together. There can besecondary materials added to the cuff for stiffness, support ordefinition. These may include metallic elements, polymer segments,composite materials.

FIGS. 5A and 5B illustrate an example of such the embodiment describedabove. In the illustrated embodiment, the body 102 defines a generallysleeve shaped lumen 132. The top surface 134 of the body 102 isscalloped shaped. The peaks or commissars 136 of the top surface 134 aresupported by elongated members 138 positioned within or along the outersurface of the body 102. The leaflets 104 are supported within the body102 with its edges corresponding to the supported commissars 136. Themembers 138 can comprise metallic wire or laser-cut elements. Theseelements 138 may be attached by conventional techniques such as sewing,gluing or woven to the body 102. The elements 138 can range in crosssection from round, oval, square or rectangular. Dimensionally they canhave a width and or thickness from 0.002 to 0.030 inches. Materials forthese elements 138 can be stainless steel, Nitinol, Cobalt-Chromium suchas MP35N or other implant grade materials. These elements 138 canprovide visualization under conventional imaging techniques such asfluoroscopy, echo, or ultrasound. Radiopaque markers may be desired todefine the proximal and distal ends of the cuff and these markers may bematerials such as gold, platinum iridium, or other materials that wouldprovide an imaging element on body 102

FIG. 6 illustrates another embodiment of the valve 100, which includes abody 102, with distal and proximal ends 126, 128 supported by rings (notshown) as described above. As compared to the embodiment of FIGS. 3A and3B, in this embodiment, the inflatable struts 114 are replaced byelongated stiffening members 140. The stiffening members 140 can bepositioned on the body 102 to generally correspond to the commissars 136of a scalped to surface 134 as described above. The stiffening members140 can be coupled to the body 102 in any of a variety of manners. Inthe illustrated embodiment, the stiffening member 140 are coupled to thebody 102 through a combinations of sutures 112 and loops 142 that extendthrough the body 102.

The stiffening members 140 can be metallic wire, ribbon or tube. Theymay vary in thickness from 0.005 to 0.050 inches and taper or vary inthickness, width or diameter. As mentioned embodiment, the members 140can be used to support the valve commissars 136, and/or define theheight of the cuff or be attachment points for the deployment catheter.These members 140 may be sewn to or woven into the cuff material 106through conventional techniques as described above and may be shapedwith hoops to accept thread or wires. The members 140 may also be formedfrom a hypotube, allowing deployment control wires or a deploymentcontrol system as will be described below to pass through the stiffeningwires or to attach to them. Other lengths of stiffening wires are alsopossible, in some instances a shorter wire may be preferred, either toallow a smaller profile, better conform to a calcified valve annulus, orto ensure positive engagement of an anchor. Short sections of stiffeningwires may also be positioned in directions other than the axialdirection. Positioning wires off axis may allow the valve to move morenaturally relative to the native tissue, or prevent anchors fromrotating and disengaging. The stiffening members 140 may besubstantially straight pieces of wire.

FIGS. 7A and 7B illustrate yet another embodiment of the implant 100 inwhich substantially the entire body 102 is filled with fluid creating anhour glass shape. Between the proximal and distal ends 126, 128, thebody 102 includes axially extending channels 46 which form axiallyextending lumens 48 for extending over the native valve or valve stem.

In the embodiments described herein, the inflation channels 120 may beconfigured such that they are of round (see FIG. 8A), oval, square (FIG.10), rectangular (see FIG. 9B) or parabolic shape in cross section.Round cross sections may vary from 0.020-0.100 inches in diameter withwall thicknesses ranging from 0.0005-0.010 inches. Oval cross sectionsmay have an aspect ratio of two or three to one depending upon thedesired cuff thickness and strength desired. In embodiments in which thelumens 120 are formed by balloons 111, these lumens 120 can beconstructed from conventional balloon materials such as nylon,polyethylene, PEEK, silicone or other generally accepted medical devicematerial. They may be helically coiled into a cylinder shape creating atube (see FIG. 8A) or looped radially to create a series of toroids (seeFIG. 9A) or undulate (see FIG. 3C) to create a sinusoidal pattern toprovide support both radially and axially. A combination of thesepatterns may be desired to best suit the patient and desired valve. Forexample, a combination of single a single toroid proximal and distal maybe the preferred pattern however any number of toroids may be locatedbetween proximal and distal portions of the device to provide additionaltissue and or calcium support throughout the height of the device.

With reference now to FIGS. 11 and 12, the implant 100 can include oneor more windows 150 cut or otherwise formed in the body 102 of the valve120 to supply blood to the coronary arteries 152. The number of windows150 can range from one to twenty. In the illustrated embodiment, thewindows 150 are generally located radially between the proximal anddistal ends 126, 128. Depending upon the configuration of the implant100, these windows 150 can be defined, at least in part, by inflationlumens, support structures such as metallic or polymer struts or be cutinto the body material as a step in the manufacturing process. In oneembodiment, the locations of the windows 150 is denoted by radio-opaquemarkers to ensure the proper orientation of the windows 150. In anotherembodiment, the rotational orientation of the implant 100 is controlledby the orientation that the implant 100 is loaded into the deploymentcatheter 300. In this embodiment, the deployment catheter 300 can have apreset curve or a preferred bending plane, oriented such that as thecatheter 300 is delivered over the aortic arch or some other nativeanatomy, the implant 100 is oriented in the proper rotational position.The area of the windows 150 is preferably between about 1 squarecentimeter and about 6 square centimeters. In one embodiment, the areaof the window 150 is between about 1.5 square centimeters and about 3square centimeters. A larger sized window advantageously can permit sometolerance in the placement of the window 150 relative to the coronaryostia. Windows 150 may also be placed in a stent segment of a prostheticvalve.

In other embodiments configured for maintaining patent flow through thecoronary arteries 152, the cuff 102 has an open mesh structure thatallows patent flow in any orientation. The mesh structure is preferablysufficiently configured that not more than one or two of its threads orwires would cross an ostium at any position. It is also possible toaccess the coronary arteries with an angioplasty balloon and deform themesh structure away from the ostium, provided that the mesh ismanufactured from a plastically deformable material, such as stainlesssteel, or any of the biocompatible materials with similarly appropriatemechanical properties.

In order to visualize the position and orientation of the implant 100,portions of the body 102 would ideally be radio-opaque. Markers madefrom platinum gold or tantalum or other appropriate materials may beused. These may be used to identify critical areas of the valve thatmust be positioned appropriately, for example the valve commissures mayneed to be positioned appropriately relative to the coronary arteriesfor an aortic valve. Additionally during the procedure it may beadvantageous to catheterize the coronary arteries using radio-opaquetipped guide catheters so that the ostia can be visualized. Specialcatheters could be developed with increased radio-opacity or larger thanstandard perfusion holes. The catheters could also have a reduceddiameter in their proximal section allowing them to be introduced withthe valve deployment catheter.

As mentioned above, during delivery, the body 102 is limp and flexibleproviding a compact shape to fit inside a delivery sheath. The body 102is therefore preferably made form a thin, flexible material that isbiocompatible and may aid in tissue growth at the interface with thenative tissue. A few examples of material may be Dacron, ePTFE, PTFE,TFE, woven material such as stainless steel, platinum, MP35N, polyesteror other implantable metal or polymer. As mentioned above with referenceto FIG. 2, the body 102 may have a tubular or hyperboloid shape to allowfor the native valve to be excluded beneath the wall of the cuff. Withinthis body 102 the inflation channels 120 can be connected to a catheterlumen for the delivery of an inflation media to define and add structureto the implant 100. As described above, these channels 120 can have anyof a variety of configurations. In such configurations, the channels 120may number from one to fifty and may have a single lumen communicatingto all channels or separate lumens for communication separate channelsor groups of channels. In one embodiment, the cuff or sleeve 102contains 2 to 12 lumens, in another the cuff 102 contains 10 to 20lumens. As described above, the channels 120 can be part of or formed bythe sleeve 102 material 106 and/or be a separate component attached tothe cuff such as balloon 111. The valve 104, which is configured suchthat a fluid, such as blood, may be allowed to flow in a singledirection or limit flow in one or both directions, is positioned withinthe sleeve 102. The attachment method of the valve 104 to the sleeve 102can be by conventional sewing, gluing, welding, interference or othermeans generally accepted by industry.

The cuff 102 would ideally have a diameter of between 15 and 30 mm and alength of between 6 to 70 mm. The wall thickness would have an idealrange from 0.01 mm to 2.00 mm. As described above, the cuff 102 may gainlongitudinal support in situ from members formed by fluid channels orformed by polymer or solid structural elements providing axialseparation. The inner diameter of the cuff 102 may have a fixeddimension providing a constant size for valve attachment and apredictable valve open and closure function. Portions of the outersurface of the cuff 102 may optionally be compliant and allow theimplant 100 to achieve interference fit with the native anatomy.

Many embodiments of inflatable structure 107 shapes have been describedabove. In addition, as described above, the implant 100 can have variousoverall shapes (e.g., an hourglass shape to hold the device in positionaround the valve annulus, or the device may have a different shape tohold the device in position in another portion of the native anatomy,such as the aortic root). Regardless of the overall shape of the device,the inflatable channels 120 can be located near the proximal and distalends 126, 128 of the implant 100, preferably forming a configurationthat approximates a ring or toroid. These channels 120 may be connectedby intermediate channels designed to serve any combination of threefunctions: (i) provide support to the tissue excluded by the implant100, (ii) provide axial and radial strength and stiffness to the 100,and/or (iii) to provide support for the valve 104. The specific designcharacteristics or orientation of the inflatable structure 107 can beoptimized to better serve each function. For example if an inflatablechannel 120 were designed to add axial strength to the relevant sectionof the device, the channels 120 would ideally be oriented in asubstantially axial direction. If an inflatable channel 120 weredesigned primarily to add radial strength to the relevant section of thedevice the channel would ideally be oriented generallycircumferentially. In order to prevent tissue from extending between theinflatable channels the channels 120 should be spaced sufficiently closetogether to provide sufficient scaffolding.

Additionally depending on the manufacturing process used certainconfigurations may be preferred. For example a single spiraling balloon(see e.g., FIG. 8A) that forms the proximal, mid and distal inflationchannels may be simplest to manufacture if a balloon is placed within asewing cuff as described with referenced to FIG. 3C. FIG. 3D illustratesan embodiment that utilizes rings 108 and struts 114 that are positionedwithin folds 110 of the cuff 102.

In other embodiments, the implant 100 is manufactured from multiplelayers that are selectively fused together, then the inflation channels120 are defined by the unfused or unjoined areas between fused areas152. In this case any of a variety configurations of inflation channels120 can be used. For example, as shown in FIG. 13A, the implant 100 cancomprise distal and proximal rings 108 with undulating channels 120positioned therebetween. FIG. 13B illustrates an embodiment in which theinflation 120 generally formed a cylinder with axially extending fusedportions forming axially extending ribs 156. FIG. 13C is similar to theembodiment of FIG. 13B, however, the fused portions 152 are larger toform narrow ribs 156. In these embodiments, the inflation channels 120are preferably configured so that the inflation media can flow into allof the channels without forming pockets of trapped air or pre inflationfluid.

The cuff 102 and inflation channels 120 of the implant 100 can bemanufactured in a variety of ways. In one embodiment the cuff 102 ismanufactured from a fabric, similar to those fabrics typically used inendovascular grafts or for the cuffs of surgically implanted prostheticheart valves. The fabric is preferably woven into a tubular shape forsome portions of the cuff 102. The fabric may also be woven into sheets.The yarn used to manufacture the fabric is preferably a twisted yarn,but monofilament or braided yarns may also be used. The useful range ofyarn diameters is from approximately 0.0005 of an inch in diameter toapproximately 0.005 of an inch in diameter. Depending on how tight theweave is made. Preferably, the fabric is woven with between about 50 andabout 500 yarns per inch. In one embodiment, a fabric tube is woven witha 18 mm diameter with 200 yarns per inch or picks per inch. Each yarn ismade of 20 filaments of a PET material. The final thickness of thiswoven fabric tube is 0.005 inches for the single wall of the tube.Depending on the desired profile of the implant 100 and the desiredpermeability of the fabric to blood or other fluids different weaves maybe used. Any biocompatible material may be used to make the yarn, someembodiments include nylon and PET. Other materials or other combinationsof materials are possible, including Teflon, floropolymers, polyimide,metals such as stainless steel, titanium, Nitinol, other shape memoryalloys, alloys comprised primarily of a combinations of cobalt,chromium, nickel, and molybdenum. Fibers may be added to the yarn toincreases strength or radiopacity, or to deliver a pharmaceutical agent.The fabric tube may also be manufactured by a braiding process.

The cut edges of the fabric are melted or covered with an adhesivematerial, or sutured over, in order to prevent the fabric fromunraveling. Preferably the edges are melted during the cutting process,this can be accomplished using a hot-knife. The blade of the tool isheated and used to cut the material. By controlling temperature and feedrate as well as the geometry of the blade, the geometry of the cut edgeis defined. In one embodiment the hot knife blade is 0.060 inches thicksharpened to a dull edge with a radius of approximately 0.010 inches.The blade is heated to approximately 400 degrees F. and used to cutthrough a Dacron fabric at a speed of about 20 inches per minute.Preferably the cutting parameters are adjusted so that the cut edge issealed with a thin layer of melted fabric, where the melted area issmall enough to remain flexible, and prevent cracking, but thick enoughto prevent the fabric from unraveling. The diameter of the bead ofmelted fabric is preferably between 0.0007 and 0.0070 inches indiameter.

Two edges of a fabric may be sealed together by clamping the edgestogether to form a lap joint, and then melting the free edge. This maybe accomplished with a flame, laser energy, a heated element thatcontacts the fabric, such as a hot-knife or a heating element thatpasses near the fabric, or a directed stream of a heated gas such asair. The bead of melted fabric joining the two edges is preferablybetween 0.0007 and 0.0070 inches in diameter.

The fabric is stitched, sutured, sealed, melted, glued or bondedtogether to form the desired shape of the implant 100. The preferredmethod for attaching portions of the fabric together is stitching. Thepreferred embodiment uses a polypropylene monofilament suture material,with a diameter of approximately 0.005 of an inch. The suture materialmay range from 0.001 to 0.010 inches in diameter. Larger suturematerials may be used at higher stress locations such as where the valvecommissures attach to the cuff. The suture material may be of anyacceptable implant grade material. Preferably a biocompatible suturematerial is used such as polypropylene. Nylon and polyethylene are alsocommonly used suture materials. Other materials or other combinations ofmaterials are possible, including Teflon, fluoropolymers, polyimides,metals such as stainless steel, titanium, Kevlar, Nitinol, other shapememory alloys, alloys comprised primarily of a combinations of cobalt,chromium, nickel, and molybdenum such as MP35N. Preferably the suturesare a monofilament design. Multi strand braided or twisted suturematerials also may be used. Many suture and stitching patterns arepossible and have been described in various texts. The preferredstitching method is using some type of lock stitch, of a design suchthat if the suture breaks in a portion of its length the entire runninglength of the suture will resist unraveling. And the suture will stillgenerally perform its function of holding the layers of fabric together.

FIG. 13D illustrates another embodiment of an implant 100 in which anouter portion 156 of the cuff 102, which is in contact with thecalcified annulus contains a material selected for its abrasionresistance. In one embodiment, the abrasion resistant material is asynthetic fiber such a Kevlar or other Aramid fiber. In anotherembodiment, the abrasion resistant material is a metal such as MP35N orstainless steel. In one embodiment, the fabric is woven entirely fromthe abrasion resistant material. In another embodiment, the fabric iswoven from a combination of materials including an abrasion resistantmaterial and a second material, designed to optimize other properties,such as tissue in-growth. The fibers of different materials may betwisted together into a single yarn, or multiple yarns of differentmaterials may be woven together as the fabric is manufactured.Alternatively, an abrasion resistant layer may be added to the outsideof the finished device or implanted first as a barrier or lattice toprotect the valve device.

As mentioned above, the cuff 102 may be manipulated in several ways toform inflation channels 120. In many embodiments, the implant 100 is notprovided with separate balloons 111, instead the fabric 106 of the cuff102 itself can form the inflation channels 100. For example, in oneembodiment two fabric tubes of a diameter similar to the desired finaldiameter of the implant 100 are place coaxial to each other. The twofabric tubes are stitched, fused, glued or otherwise coupled together ina pattern of channels 120 that is suitable for creating the geometry ofthe inflatable structure 107. In one embodiment the stitching patternconsists of a spiral connecting the two tubes. The spiral channel formedbetween the sutured areas becomes the inflation channel (see e.g., FIG.8A). In another embodiment the two coaxial fabric tubes are actually asingle tube folded over its self. In another embodiment, the tubes aresewn together in a pattern so that the proximal and distal ends of thefabric tubes form an annular ring or toroid. See e.g., FIG. 13C. In yetanother embodiment of the design the middle section of the devicecontains one or more inflation channels shaped in a sinusoidal pattern.See e.g., FIG. 13A.

With reference to FIG. 14, in another embodiment, the implant 100 isformed from a single fabric tube 160 similar to the final diameter ofthe implant 100. Smaller fabric tubes 162 of a diameter suitable for aninflation channel are attached to the larger tube 160. The smaller tubes162 can be attached to the inside or the outside of the larger tube 160in any pattern desired to provide the inflatable structure 107 with thedesired properties. In one embodiment, the tubes 162 are attached in aspiral pattern, in another embodiment the tubes 162 are attached in asinusoidal pattern simulating the shape of the connection of the leafletto the cuff. As shown in FIG. 14, an optional skived hypotube or similarcomponent 164 can be positioned within the smaller tubes 162. Thesmaller tubes 162 can be sutured, glued, fused or otherwised coupled tothe larger tube 160. In the illustrated embodiment, sutures 112 appliedvia a needle 166 and thread 168 to secure the smaller tube 162 to thelarger tube 164.

In another embodiment, a single fabric tube similar to the finaldiameter of the prosthetic implant 100 is used. The ends or an end ofthe tube is turned inside out forming two layers of tube for a shortlength at one or both ends of the tube. The layers of tube are sewn orotherwise attached together to form a ring shaped inflation channel atthe end of the tube in a manner similar to that shown in FIG. 3C.Alternatively the layers may be sewn together in a different pattern toform an inflation channel with a different shape such as a spiral or asinusoid.

If a porous fabric is used for the cuff 102, it may be desired to use aliner (e.g., as shown in FIG. 14) or coating to prevent the inflationmedia from escaping from the inflation lumens 120. This portion of thefabric may be coated, filled or encapsulated in a polymer or otherdealing agent to better seal the fabric. The entire fabric portion maybe treated or, a specific portion of the fabric may be treated. Thefabric may be treated before the cuff 102 is manufactured, or after thecuff 102 is manufactured. In one embodiment, the treatment is a polymersuspended in a solvent. After the solvent evaporates or is otherwiseremoved the polymer is left behind sealing the fabric. In anotherembodiment, the sealing agent is applied as a liquid or paste, and thencured by moisture, heat external energy, such as UV light, light ofanother wave length or a chemical reaction caused by mixing two or morecomponents together. In another embodiment, the sealing agent is asilicone.

In the preferred embodiment, the fabric inflation channels contain aliner in a form of the balloons 111 as described with reference to FIGS.3A-C. The balloon 111 preferably is a thin wall tube made from abiocompatible material. In one embodiment, the balloon 111 is blown fromnylon tubing the tubing diameter is about 0.030 of an inch with a 0.005inches wall thickness. The tubing is then necked to an outside diameterof approximately 0.020 inches the tubing is then placed inside a moldand pressurized to about 200 PSI the mold is then heated in the areawhere the balloon should be formed. The heating step may be accomplishedusing a stream of heated air at approximately 300 degrees F. The finaldiameter of the balloon in this embodiment is 0.060 inches at oneportion of the balloon and 0.090 inches a second portion of the balloon.The total length of the balloon 111 is approximately 18 cm. The balloon111 may be blown in a shape that conforms to the cuff, or the balloonmay be shaped to conform to the cuff in a secondary step. Alternativelythe liner may be a different shape than the fabric cuff, where the lineris larger than the fabric cuff, allowing the assembly to inflate to asize determined by the fabric.

Several embodiments of the inflatable prosthetic implant 100 describedabove utilize circular or ringed shaped balloon members 111. Theseballoons 111 can be manufactured using a glass tube bent in a helix. Theballoon 111 is then blown inside the tube using methods similar to thoseused to manufacture balloons for angioplasty. For example, the glassmold may be heated using air, water, steam infrared elements andpressure and tension may be applied to blow the balloon to a specificdiameter and length. Secondary processes may be added to “set” theballoon's shape by providing a second heating process to hold theballoon as it relaxes and ages. The balloons can be blown from manydifferent materials; Nylon pebax and polyethylene are particularlysuitable polymers. The balloon tubing is inserted through the mold, andsealed at one end. A knot tied in the tubing is sufficient for sealing.The other end of the tubing is connected to a pressure source, providingpressure in the range of 80 to 350 psi. The required pressure depends onthe material and dimensions of the tubing. The balloon is then heated ina localized area, while tension is optionally applied to either end ofthe tubing. After the tubing expands to match the inside diameter of theglass mold, the heat source is advanced along the length of the mold, ata rate that allows the tubing to grow to match the inside diameter ofthe mold. The balloon and mold may then be cooled. One method forcooling is blowing compressed air over the mold. The balloon is thenremoved from the mold. Optionally a release agent may be used tofacilitate this step. Acceptable mold release agents include silicone,Polyvinyl alcohol (PVA) and Polyethylene oxide (PEO) Additionallyballoons may be produced by wrapping braiding or weaving a material suchas EPTFE over a mandrel to produce a shape desired the material is thenbonded to itself by a process such as sintering or gluing.

With reference back to FIGS. 3A-D, in a preferred embodiment, theimplant 100 is manufactured from a single layer of woven fabric tube 106of a diameter similar to the desired diameter of the finished prostheticvalve. The diameter of the tube 106 is approximately 1 inch. A length oftube 106 approximately 1.2 inches long is used. The ends of the tube 106are cut using a hot knife to prevent the edges from unraveling. A secondpiece 115 of woven fabric tubing with a diameter of approximately 0.065inches is cut to length of approximately 7 inches long using a hot-knifeso that the edges of the tube 115 do not unravel. The smaller diametertube 115 is then sewed to the middle portion of the inner diameter ofthe larger diameter fabric tube 106, in a shape producing three cuspsnear the top edge of the fabric tube 106. The cusps are locatedapproximately 0.15 inches from the top edge of the fabric tube 106. Theportion of the smaller tube 115 between the cusps is sewed to the middlesection of the larger diameter tube, in approximately a 0.5 inches inradius. The bottom portion of the radius is positioned about 0.27 inchesfrom the bottom edge of the larger diameter fabric tube 106. The bottomedge of the larger diameter fabric tube 106 is then folded inside outover its outside diameter. A suture 112 is placed through the two layersof the larger diameter fabric tube 106, located about 0.1 inches fromthe folded edge. This suture 112 is spaced approximately 0.05 inch fromthe cut edge of the fabric tube 106, and approximately 0.05 in from thelower edge of the radii formed from the attachment of the smallerdiameter fabric tube 115.

With reference to FIG. 15, in the embodiment of FIG. 3A-D, a tubularsection of the valve 104 (preferably fixed pericardial tissue, ofapproximately 1 inches in diameter and 0.6 inches in length) is insertedinto the inside diameter of the larger fabric tube 106. Small squares offabric 166 approximately 0.08 inches by 0.18 inches are placed at eachvalve cusp inside the tubular section of pericardial tissue 104. Sutures168 are passed through the square of fabric and the pericardial tissue104, and then between two segments of the smaller diameter fabric tube115 that form the cusp 116, and through the larger diameter fabric tube106. In this manner, the top edge of the pericardial tissue tube isattached to the cuff 102 at the three locations that form the cusps 116and valve commissures. The bottom edge of the pericardial tissue tube isthen attached to the bottom edge of the cuff 102 by suturing the tissuein the location between the smaller fabric tube 115 and the suture thatforms the bottom ring shaped inflation channel.

The balloon members 111 are then placed inside each channel formed bythe cuff 102. See e.g. FIG. 3C. In another embodiment, the cuff 102 ismanufactured from a nonporous polymer sheet or tube, or from polymersheet or tube with minimal porosity, where a secondary sealing membersuch as a balloon is not required.

FIGS. 16A and 16B illustrate a modified embodiment a stented implant 170that can be delivered percutaneously as described by Andersen in U.S.Pat. No. 6,168,614, which is hereby incorporated by reference herein.The implant 170 generally comprises a stent-like structure 172 thatcomprises a one or more elongated members arranged in an annular zig-zagpattern comprising proximal and distal bends to form a self-expandablestent. A valve 174 is coupled to the structure 172. The implant 170 caninclude one (FIG. 16A) or more (FIG. 16B) inflatible cuffs 176configured in a manner as described above. The inflatable cuff 176 isconfigured to minimize or eliminate peri-valvular leaks. For example,the inflatable cuff 176 can be positioned on the implant 170 so thatwhen it is in inflated it prevents or restricts fluid flow around thefixed edge of each leaflet of the valve 174. In the embodiment of FIG.16A, the valve 170 includes a single circular cuff 174 attached to theouter surface of the stent 172 in a location where the fixed edge of theleaflets of the valve 174 are attached to the stent 172. After the stent172 is expanded, the inflatable cuff 176 is filled with inflation media.The cuff 176 is inflated to a pressure adequate to seal the outersurface of the implant 170 to the native anatomy. A passive structuresuch as an O-ring that has no inflatable passage but does serve to forma seal between the vessel wall and the valve 174 could also be provided.In such an embodiment, the sealing structure is preferably made from alow durometer material or foam so that it can easily conform to theanatomy. A silicone or silicone foam can also be used to produce anadequate sealing member.

Another problem with an expandable stent based valve prosthesis is thatif the stent is over-expanded the valve leaflets may not coapt. Thisresults in a central leak, and an incompetent valve. In one embodiment,the inflatable sealing cuff 176 described above is designed so that ifthe operator detects a central leak the operator can inflate the cuff toa high pressure causing the stent 172 to decrease in diameter at theprosthetic valves annulus. The operator monitors any regurgant flowusing an imaging technique such as echocardiography. Guided by thisinformation the cuff 176 can be inflated to the minimum pressure thateliminates the leak. Using the minimum pressure insures that the maximumpossible area is available for blood flow. This technique would allowfor a reduction in the initial deployed diameter or a resizing of thestructure to properly fit the implantation area.

Non-Inflatable Prosthetic Aortic Valve Implants

FIGS. 17A-20A illustrate another embodiment of a implant 180, whichutilizes a different technique to secure a valve 182 at the implantationsite. In this embodiment, the implant 180 comprises at least one member184 that is attached to the valve 182 and provides the valve 182 shapeas it is deployed into the body. In general, the member 184 forms a ringor annular shape when it is actuated and deployed. However, duringdelivery the member 184 is flexible and generally elongated with areduced profile, while the leaflets 183 of the valve 182 are wrappedaround the support member 184 (see FIGS. 20 and 20A) so as to passthrough a delivery catheter. During deployment leaflets 183 of the valve182 unwrap and take a second shape to form a seal with the vessel andfunction as a single direction gate for blood flow. See also FIGS. 21Aand 21B which show the deployment of the valve 180 within the heart 10.

A latch or lock mechanism 181 maintains the tension in the wire or locksthe distal end to a location near the proximal end. This tensionmechanism may be driven from the handle through a tension wire, ahydraulic system, a rotational member to drive a screw. Furthermore thetensioning members may utilize a locking means to maintain the desiredcircular shape, such as a suture, an adhesive, or a mechanical snaptogether type lock actuated by the tension wire.

With initial reference to FIGS. 18A-C, in one embodiment the structure184 or a portion of the structure, is manufactured from a stainlesssteel tube 185 with slots 188 cut on one side (e.g., as seen inPublished Application number US 2002/0151961 A1, which is herebyincorporated by reference herein) to provide flexibility duringdelivery. A wire 186 located inside the tube is tensioned providing abias to shape the device as determined by the patterning and width ofthe transverse slots 188 cut into the member 184. These slots 188 andtension wire 186 cause the device to form into a circular shape as shownin FIGS. 17A and 18C. In another embodiment, the slots 188 can beoriented such that the ring is three dimensional, possibly incorporatingcusps or high points at the valve commissars as shown in FIG. 17B.Additionally, the member may incorporate integral struts 190 to supportthe commissars of the valve 182 as shown in FIG. 17A.

FIGS. 19B and 19C illustrate an embodiment in which the slots 188 have achevron type shape. The wire inside the device is tensioned providing abias to shape the device as determined by the patterning and width ofthe transverse slots 188, causing the device to form into a circularshape as shown in FIG. 19C. In another embodiment, the slots 188 can beoriented such that the ring has a three dimensional shape whentensioned.

FIGS. 22A and type shape 22B illustrate a modified embodiment in whichthe member 180 is formed from elements 191 that are configured toprovide the member 180 with a preformed shape as the member 180 isrotated. For example, as shown in the figures, the elements 191 may havea trapezoidal shape.

FIG. 23 illustrates an embodiment of an implant 194 in which the implant194 comprises a ring 195. As shown, the device 194 can be constrained ina catheter by bending the ring 105 into an oval with a large aspectratio. Once expelled from the catheter, the implant 194 would assume itsfree state of a circle or more round shape. A tissue valve 196 could beattached by conventional manners such as sewing or seaming the tissuetogether. FIGS. 24A and 24B illustrate a similar embodiment in which thering 195 has an undeformed configuration that includes elongated members197.

FIGS. 25A-C illustrate another modified embodiment in which the ring 195needs to be assembled in situ. In this embodiment, the ring 195comprises a series of distal and proximal bends 197 a, 197 b. As shownin FIG. 25B, the ring 195 can be elongated and compressed for deliveryvia a catheter. Once expelled from the catheter, the ring 195 isassembled by coupling together connection points 199 a, 199 b throughthe use of sutures etc.

In the embodiments described above with reference to FIGS. 17A-17C, theimplant must be released or disconnected from a delivery catheter. Thoseof skill in the art will recognize in light of the disclosure hereinthat many different release disconnect methods are possible. For exampleif rotational motion is used to deploy the device, then a disconnectthat can transmit torque is typically provided such as a threadedconnection. In other embodiments, the device is pushed out of thecatheter by a pusher element. In still other embodiments, a mechanicalrelease mechanism such as a pin joint, unscrewing the device from thecatheter delivery system, a tethered link such as a thread or wire, afusible link as used in a GDC coil deployment, a cutting tool to sever aattachment of the device from the catheter, a threaded knot to tetherthe catheter to the device where the as the knot could be untied or cut,a hydraulic mechanism to deploy, expand or fracture a link between thecatheter and the device.

FIG. 25D illustrates another embodiment of a prosthesis 700. In thisembodiment, the prosthesis 700 includes a flexible fabric cuff 702. Thefabric cuff 702 includes one or more channels 704 where a permanentsupport structure 706 can later be located. In one embodiment, thepermanent support structure is woven through the channels 704 that willlater contain the support structure. In another embodiment, the supportstructure 706 is preloaded into the cuff in a flexible configuration. Inone embodiment of use, a catheter contains at least one lumen throughwhich the support structure can be advanced and the assembly can befitted inside a retractable delivery sheath. The cuff 702 is deliveredto the desired valve annulus, and the support structure 706 is advancedinto a portion (e.g., a channel 704) of the device 700. This providesstructure to the prosthesis 700 such that it can support a valve (notshown) that is coupled to the cuff 702, and allows it to be positionedin the native annulus and to function. In one embodiment, the supportstructure 706 is a wire. If the operator is satisfied with the size andposition of the prosthesis 700 additional support structure may be addedto stiffen or secure the prosthesis 700. After the prosthesis 700 ispositioned the delivery catheter may optionally be withdrawn ordisconnected, leaving, the valve cuff 702 and support structure 706 inplace. Alternatively, the delivery catheter may be left in place for anylength of time to allow later adjustment or removal of the prosthesis700.

In the illustrated embodiment, the cuff 702 contains a spiral channel704 allowing the delivery of a wire 706, which takes a helical shapeafter it is inserted into the cuff. The helix extends from the proximalend of the device 700 to the distal end of the valve with the individualcoils spaced close together as shown in FIG. 25D.

The preferred wire material is Nitinol, although many other metals andpolymers have suitable properties. Nitinol provides an advantage thatits chemistry and thermal history can be used to tune the temperature atwhich it undergoes a phase change. By adjusting this transitiontemperature to fall at a temperature just below body temperature thesupport structure 706 can be delivered (e.g., within the cuff 702) withone set of mechanical properties and after delivery, and after thesupport structure 706 has equalized in temperature with the body, thesupport structure 706 assumes a second set of mechanical properties(e.g., shape). Other materials that undergo a phase change near bodytemperature, such as other shape memory alloys may provide similarbenefits.

In one embodiment, the catheter that is attached to the channels 704 inthe cuff 702 is preferably in an orientation that allows the wire 706 tobe delivered with minimal friction making a minimum number ofexcessively sharp bends. The catheter may optionally include aninflation portion to allow an inflation media to temporarily act as asupport structure during the process of positioning the prosthesis 700.

FIGS. 25E and 25F illustrate another embodiment of a prosthesis 750. Inthis embodiment, the prosthesis 750 includes a flexible fabric cuff 752,which can be coupled to a valve 754. As shown in FIG. 25E, theprosthesis 750 has a highly flexible shape in this configuration, whichdelivery within a catheter. Once the device 750 is positioned near thedelivery site, the device 750 can be given structure through the use ofone or more stents 756. The stents 756 can be self-expandable or balloonexpandable. In the illustrated embodiment, the stents 756 are positionedgenerally at the proximal and distal ends of the device 750. The stents756 provide structure to the prosthesis 750 such that it can support thevalve 754 that is coupled to the cuff 752, and allows it to bepositioned in the native annulus and to function.

Leaflet Subassembly

With reference back to the embodiments of FIGS. 1-16B, the valve 104preferably is a tissue-type heart valve that includes a dimensionallystable, pre-aligned tissue leaflet subassembly. Pursuant to thisconstruction, an exemplary tissue valve 104 includes a plurality oftissue leaflets that are templated and attached together at their tipsto form a dimensionally stable and dimensionally consistent coaptingleaflet subassembly. Then, in what can be a single process, each of theleaflets of the subassembly is aligned with and individually sewn thecuff 102, from the tip of one commissure uniformly, around the leafletcusp perimeter, to the tip of an adjacent commissure. As a result, thesewed sutures act like similarly aligned staples, all of which equallytake the loading force acting along the entire cusp of each of thepre-aligned, coapting leaflets. Once inflated, the cuff 102 supports thecommissures with the inflation media and its respective pressure whichwill solidify and create a system similar to a stent structure. Theresulting implant 100 thereby formed reduces stress and potentialfatigue at the leaflet suture interface by distributing stress evenlyover the entire leaflet cusp from commissure to commissure. Thisimproved, dimensionally stable, reduced-stress assembly is operativelyattached to the top of a previously prepared cloth-covered cuff 102 toclamp the tissue leaflet cusps on a load-distributing cloth seat formedby the top of the cloth-covered cuff without distorting the leaflets ordisturbing their relative alignment and the resultant coaptation oftheir mating edges. Because the tissue leaflets experience lower, moreevenly distributed stresses during operation, they are less likely toexperience distortion in use. Thus, a more stable, long lived,functional closure or coaptation of the leaflets is provided by thiseven distribution of attachment forces.

A number of additional advantages result from the use of the implant 100and the cuff 102 construction utilized therein. For example, for eachkey area of the cuff 102, the flexibility can be optimized orcustomized. If desired, the coapting tissue leaflet commissures can bemade more or less flexible to allow for more or less deflection torelieve stresses on the tissue at closing or to fine tune the operationof the valve. Similarly, the base radial stiffness of the overall valve100 structure can be increased or decreased by pressure or inflationmedia to preserve the roundness and shape of the valve 100.

Attachment of the valve 104 to the cuff 102 can be completed in anynumber of conventional methods including sewing, ring or sleeveattachments, gluing, welding, interference fits, bonding throughmechanical means such as pinching between members. An example of thesemethods are described in Published Application from Huynh et al U.S.Pat. No. 6,102,944 or Lafrance et al 2003/0027332 or Peredo U.S. Pat.No. 6,409,759, which are hereby incorporated by reference herein. Thesemethods are generally know and accepted in the valve device industry. Asmentioned above, the cuff 102 may additionally house an inflation moldwhere the structure is formed within the body or the cuff made be themold where the fluid is injected to create the support structure. Thevalve, whether it is tissue, engineered tissue, mechanical or polymer,may be attached before packaging or in the hospital just beforeimplantation. Some tissue valves are native valves such as pig, horse,cow or native human valves. Most of which are suspended in a fixingsolution such as Glutaraldehyde.

Although mechanical heart valves with rigid pivoting occluders orleaflets have the advantage of proven durability through decades of use,they are associated with blood clotting on or around the prostheticvalve. Blood clotting can lead to acute or subacute closure of the valveor associated blood vessel. For this reason, patients with implantedmechanical heart valves remain on anticoagulants for as long as thevalve remains implanted. Anticoagulants impart a 3-5% annual risk ofsignificant bleeding and cannot be taken safely by certain individuals.

Besides mechanical heart valves, heart valve prostheses can beconstructed with flexible tissue leaflets or polymer leaflets.Prosthetic tissue heart valves can be derived from, for example, porcineheart valves or manufactured from other biological material, such asbovine or equine pericardium. Biological materials in prosthetic heartvalves generally have profile and surface characteristics that providelaminar, nonturbulent blood flow. Therefore, intravascular clotting isless likely to occur than with mechanical heart valve prostheses.

Natural tissue valves can be derived from an animal species, typicallymammalian, such as human, bovine, porcine canine, seal or kangaroo.These tissues can be obtained from, for example, heart valves, aorticroots, aortic walls, aortic leaflets, pericardial tissue such aspericardial patches, bypass grafts, blood vessels, human umbilicaltissue and the like. These natural tissues are typically soft tissues,and generally include collagen containing material. The tissue can beliving tissue, decellularized tissue or recellularized tissue.

Tissue can be fixed by crosslinking. Fixation provides mechanicalstabilization, for example by preventing enzymatic degradation of thetissue. Glutaraldehyde or formaldehyde is typically used for fixation,but other fixatives can be used, such as other difunctional aldehydes,epoxides, genipin and derivatives thereof. Tissue can be used in eithercrosslinked or uncrosslinked form, depending on the type of tissue, useand other factors. Generally, if xenograft tissue is used, the tissue iscrosslinked and/or decellularized.

The implants 100 can further include synthetic materials, such aspolymers and ceramics. Appropriate ceramics include, for example,hydroxyapatite, alumina, graphite and pyrolytic carbon. Appropriatesynthetic materials include hydrogels and other synthetic materials thatcannot withstand severe dehydration. Heart valve prostheses can includesynthetic polymers as well as purified biological polymers. Thesesynthetic polymers can be woven or knitted into a mesh to form a matrixor similar structure. Alternatively, the synthetic polymer materials canbe molded or cast into appropriate forms.

Appropriate synthetic polymers include without limitation polyamides(e.g., nylon), polyesters, polystyrenes, polyacrylates, vinyl polymers(e.g., polyethylene, polytetrafluoroethylene, polypropylene andpolyvinyl chloride), polycarbonates, polyurethanes, poly dimethylsiloxanes, cellulose acetates, polymethyl methacrylates, ethylene vinylacetates, polysulfones, nitrocelluloses and similar copolymers.Bioresorbable polymers can also be used such as dextran, hydroxyethylstarch, gelatin, derivatives of gelatin, polyvinylpyrolidone, polyvinylalcohol, poly[N-(2-hydroxypropyl)methacrylamide], poly (hydroxy acids),poly(epsilon-caprolactone), polylactic acid, polyglycolic acid,poly(dimethyl glycolic acid), poly(hydroxy buterate), and similarcopolymers. These synthetic polymeric materials can be woven or knittedinto a mesh to form a matrix or substrate. Alternatively, the syntheticpolymer materials can be molded or cast into appropriate forms.

Biological polymers can be naturally occurring or produced in vitro byfermentation and the like or by recombinant genetic engineering.Recombinant DNA technology can be used to engineer virtually anypolypeptide sequence and then amplify and express the protein in eitherbacterial or mammalian cells. Purified biological polymers can beappropriately formed into a substrate by techniques such as weaving,knitting, casting, molding, extrusion, cellular alignment and magneticalignment. Suitable biological polymers include, without limitation,collagen, elastin, silk, keratin, gelatin, polyamino acids,polysaccharides (e.g., cellulose and starch) and copolymers thereof.

A tissue-based valve prosthesis can maintain structural elements, suchas leaflets, from its native form and/or structural elements can beincorporated into the prosthesis from the assembly of distinct pieces oftissue. For example, the valve prosthesis can be assembled from aporcine heart valve, from bovine pericardium or from a combinationthereof. Porcine tissue valves, for example, the Toronto SPV® valvemarketed by St. Jude Medical, Inc. St. Paul, Minn., can be implanted inthe patient using the tools described herein. The Toronto SPV® valve isdesigned for implantation in an aortic heart valve position. See, forexample, David et al., J. Heart Valve Dis. 1:244-248 (1992). It will beappreciated by those skilled in the art that the tools of the presentinvention are applicable to any valve, especially any tissue valveprosthesis, that is adapted for implanting in a patient.

A reinforcement may be placed along the inner surface of the valvecommissure supports and/or scallops. In alternative embodiments, thereinforcement is placed on the outer surface of the valve, such as atthe valve commissure supports. The reinforcement preferably includesapertures through which the fasteners extend or can be inserted. Thereinforcements are thin strips of relatively strong material. Thereinforcement can prevent or reduce damage to the prosthesis when thefasteners are inserted and after implantation of the heart valveprosthesis in the patient. The reinforcement, thus, can protect andsupport the commissure supports from potential damage generated by thepresence of the fasteners. In alternative embodiments, the reinforcementis placed on the outside of the aorta such that the fastener pierces thereinforcement after passing through the prosthetic valve.

Tissue valves whether implanted surgically or percutaneously have a riskof calcification after implantation. To prevent or minimize thecalcification several treatments have been employed before the tissue isfixed. Some strategies include treating the valves with ethanol,metallic salts, detergents, biophosphonates, coimplants of polymericcontrolled release drug delivery systems, and covalent attachment ofanticalcifying agents. In the preferred embodiment the valve tissue istreated in 40% to 80% ethanol for 20 to 200 hours before fixation in abuffered glutaraldehyde solution. The ethanol pretreatment may preventcalcification in the valve after implantation and serves to removecholesterol and phospholipids from the tissue before fixation. (refPrevention of Bioprosthetic Heart Valve Calcification by EthanolPreincubation, Vyavahare et al)

Inflation Media

The inflatable structure 107 can be inflated using any of a variety ofinflation media 122, depending upon the desired performance. In general,the inflation media can include a liquid such water or an aqueous basedsolution, a gas such as CO2, or a hardenable media which may beintroduced into the cuff 102 at a first, relatively low viscosity andconverted to a second, relatively high viscosity. Viscosity enhancementmay be accomplished through any of a variety of known UV initiated orcatalyst initiated polymerization reactions, or other chemical systemsknown in the art. The end point of the viscosity enhancing process mayresult in a hardness anywhere from a gel to a rigid structure, dependingupon the desired performance and durability.

Useful inflation media generally include those formed by the mixing ofmultiple components and that have a cure time ranging from a few minutesto tens of minutes, preferably from about three and about twentyminutes. Such a material should be biocompatible, exhibit long-termstability (preferably on the order of at least ten years in vivo), poseas little an embolic risk as possible, and exhibit adequate mechanicalproperties, both pre and post-cure, suitable for service in the cuff ofthe present invention in vivo. For instance, such a material should havea relatively low viscosity before solidification or curing to facilitatethe cuff and channel fill process. A desirable post-cure elastic modulusof such an inflation medium is from about 50 to about 400 psi—balancingthe need for the filled body to form an adequate seal in vivo whilemaintaining clinically relevant kink resistance of the cuff. Theinflation media ideally should be radiopaque, both acute and chronic,although this is not absolutely necessary.

Details of compositions suitable for use as an inflation medium in thepresent invention are described in greater detail in U.S. patentapplication Ser. No. 09/496,231 to Hubbell et al., filed Feb. 1, 2000and entitled “Biomaterials Formed by Nucleophilic Addition Reaction toConjugated Unsaturated Groups” and U.S. patent application Ser. No.09/586,937 to Hubbell et al., filed Jun. 2, 2000 and entitled “ConjugateAddition Reactions for the Controlled Delivery of PharmaceuticallyActive Compounds”. The entirety of each of these patent applications ishereby incorporated herein by reference.

Below is listed one particular three-component medium.

This medium comprises:

(1) polyethylene glycol diacrylate (PEGDA), present in a proportionranging from about 50 to about 55 weight percent; specifically in aproportion of about 52 weight percent,

(2) pentaerthyritol tetra 3(mercaptopropionate) (QT) present in aproportion ranging from about 22 to about 27 weight percent;specifically in a proportion of about 24 weight percent, and

(3) glycylglycine buffer present in a proportion ranging from about 22to about 27 weight percent; specifically in a proportion of about 24weight percent.

Variations of these components and other formulations as described incopending U.S. patent application Ser. Nos. 09/496,231 and 09/586,937,both to Hubbell et al., may be used as appropriate. In addition, we havefound PEGDA having a molecular weight ranging from about 350 to about850 to be useful; PEGDA having a molecular weight ranging from about 440to about 560 are particularly useful.

Radiopaque materials as previously discussed may be added to this3-component system. We have found that adding radiopacifiers such asbarium sulfate, tantalum powder, and soluble materials such as iodinecompounds to the glycylglycine buffer is useful.

Applicants have found that triethanolamine in phosphate-buffered salinemay be used as an alternative to glycylglycine buffer as the thirdcomponent described above to form an alternative curable gel suitablefor use in embodiments of the present invention.

An alternative to these three-component systems is a gel made viapolymer precipitation from biocompatible solvents. Examples of suchsuitable polymers include ethylene vinyl alcohol and cellulose acetate.Examples of such suitable biocompatible solvents includedimethylsulfoxide (DMSO), n-methyl pyrrolidone (NMP) and others. Suchpolymers and solvents may be used in various combinations asappropriate.

Alternatively, various siloxanes may be used as inflation gels. Examplesinclude hydrophilic siloxanes and polyvinyl siloxanes (such as STAR-VPSfrom Danville Materials of San Ramon, Calif. and various siliconeproducts such as those manufactured by NuSil, Inc. of Santa Barbara,Calif.).

Other gel systems useful as an inflation medium or material for thepresent invention include phase change systems that gel upon heating orcooling from their initial liquid or thixotropic state. For example,materials such as n-isopropyl-polyacrylimide (NIPAM), BASF F-127pluronic polyoxyamer, and polyethylene glycol (PEG) chemistries havingmolecular weights ranging between about 500 and about 1,200 aresuitable.

Effective gels may also comprise thixotropic materials that undergosufficient shear-thinning so that they may be readily injected through aconduit such as a delivery catheter but yet still are able to becomesubstantially gel-like at zero or low shear rates when present in thevarious channels and cuffs of the present invention.

In the case of the three-component PEDGA-QT-glycylglycine formulationdescribed above, a careful preparation and delivery protocol should befollowed to ensure proper mixing, delivery, and ultimately clinicalefficacy. Each of the three components is typically packaged separatelyin sterile containers such as syringes until the appropriate time fordeploying the device. The QT and buffer (typically glycylglycine) arefirst continuously and thoroughly mixed, typically between theirrespective syringes for approximately two minutes. PEGDA is then mixedthoroughly with the resulting two-component mixture for approximatelythree minutes. This resulting three-component mixture is then ready forintroduction into the cuff as it will cure into a gel having the desiredproperties within the next several minutes. Cure times may be tailoredby adjusting the formulations, mixing protocol, and other variablesaccording to the requirements of the clinical setting. Details ofsuitable delivery protocols for these materials are discussed in U.S.patent application Ser. No. 09/917,371 to Chobotov et al.

The post-cure mechanical properties of these gels may be highlytailorable without significant changes to the formulation. For instance,these gels may exhibit moduli of elasticity ranging from tens of psi toseveral hundred psi; the formulation described above exhibits moduliranging from about 175 to about 250 psi with an elongation to failureranging from about 30 to about 50 percent.

It may be helpful to add an inert biocompatible material to theinflation material. In particular, adding a fluid such as saline to thePEGDA-QT-glycylglycine formulation (typically after it has been mixedbut before significant curing takes place) lowers the viscosity of theformulation and results in greater ease when injecting the formulationinto cuffs and channels without sacrificing the desired physical,chemical, and mechanical properties of the formulation or its clinicalefficacy. In the appropriate volume percentages, adding materials suchas saline may also reduce the potential for the inflation material suchas PEGDA-QT-glycylglycine to pose an embolic risk in case of spillage orleakage. Saline concentrations as a volume percentage of the finalsaline/three-component formulation combination may range from zero to ashigh as sixty percent or more; particularly suitable are salineconcentrations ranging from about twenty to about forty percent. Asaline volume concentration of about thirty percent to be most suitable.Alternatives to saline may include biocompatible liquids, includingbuffers such as glycylglycine.

In more general terms, it is desirable to use an inflation medium inwhich each of its components is biocompatible and soluble in blood. Abiocompatible inflation medium is desirable so to manage any toxicityrisk in the case the inflation medium were inadvertently released intothe patient's vasculature. A soluble inflation medium is desirable so tomanage any embolism risk if released into the vasculature. Such aninflation medium should not disperse nor gel or solidify if spilled intoflowing blood before curing. In the event of a spill, the normal bloodflow would then rapidly disperse the components and their concentrationwould fall below the level required for crosslinking and formation of asolid. These components would then be eliminated by the body throughstandard pathways without posing an embolic risk to the patient. Amongthe many possibilities of an inflation medium example in which all ofthe components are soluble in blood is the combination polyethyleneglycol diacrylate, a thiolated polyethyleneamine, and a buffer.

As previously discussed, more than one type of inflation medium, or morethan one variant of a single type of inflation medium may be used in asingle graft to optimize the graft properties in the region in which itis disposed.

For example, in the cuffs 102 of the various embodiments of the presentinvention, the inflation material serves as a conformable sealing mediumto provide a seal against the lumen wall. Desirable mechanicalcharacteristics for the inflation medium in the proximal and distalcuffs would therefore include a low shear strength so to enable the cuffto deform around any luminal irregularities (such as calcified plaqueasperities) and to conform to the luminal profile, as well as a highvolumetric compressibility to allow the fill material to expand thecuffs as needed to accommodate any late lumen dilatation and maintain aseal.

Another inflation media that has proven especially useful is an epoxybased two part inflation media, where one part contains the reactionproduct of epichlorohydrin and bisphenol A, and Butaneddiol diglyceridylether. And where one part contains 2,2,4-trimethyl-1, 6-hexanediamine.Whereas the material may have a viscosity of about 100-200 cPs (@100rpm/23 C) but most preferably they may be readily injected through asmall lumen to be introduced to the implant from outside the body. Theoperating temperature range may be from about −55 to about +125 C butwould be most advantageous at the body temperature of +37 C. Otherproperties may include a hardness of about 81 on the Shore D scale and alap shear strength of 1,700 PSI. An example of this would be EPO-TEK 301supplied by 14 Fortune Drive Billerica, Mass.

The mixed uncured inflation media preferably has a viscosity less than2000 cps In one embodiment the epoxy based inflation media has aviscosity of 100-200 cps. In another embodiment the inflation media hasa viscosity less than 1000 cps.

In one embodiment the inflation media contains a foaming agent. Thefoaming inflation media is beneficial because the foaming action cangenerate pressure within the inflatable portion of the device. Thereforeless inflation media needs to be injected. Additionally any pressureloss from the disconnection process is compensated for by the foamingaction of the inflation media. Many appropriate foaming medias arepossible; one example is a urethane foam.

In another embodiment the balloon or inflation channel may be connectedto the catheter on both ends. This allows the balloon to be preinflatedwith a nonsolidifying material such as a gas or liquid. If a gas ischosen CO2 or helium are likely choices, these gasses are used toinflate intraortic balloon pumps. Preferably the preinflation media isradiopaque so that the balloon position can be determined byangiography. Contrast media typically used in interventional cardiologycould be used to add sufficient radiopacity to most liquid preinflationmedias. When it is desired to make the implant permanent and exchangethe preinflation media for the permanent inflation media, the permanentinflation media is injected into the inflation channel through a firstcatheter connection. As the permanent inflation media is injected thepreinflation media is expelled out a second catheter connection. Thecatheter connections are positioned in such a way that substantially allof the preinflation media is expelled as the permanent inflation mediais injected. In one embodiment an intermediate inflation media is usedto prevent entrapment of preinflation media in the permanent inflationmedia. In one embodiment the intermediate inflation media is a gas andthe preinflation media is a liquid. In another embodiment theintermediate inflation media or preinflation media functions as a primerto aid the permanent inflation media to bond to the inner surface of theinflation channel. In another embodiment the preinflation media or theintermediate inflation media serves as a release agent to prevent thepermanent inflation media from bonding to the inner surface of theinflation channel.

The permanent inflation media may have a different radiopacity than thepreinflation media. A device that is excessively radiopaque tends toobscure other nearby features under angiography. During the preinflationstep it may be desirable to visualize the inflation channel clearly, soa very radiopaque inflation media may be chosen. After the device isinflated with the permanent inflation media a less radiopaque inflationmedia may be preferred. The feature of lesser radiopacity is beneficialfor visualization of proper valve function as contrast media is injectedinto the ventricle or the aorta.

Anchoring Mechanisms

In the embodiments described above, it may be necessary or desirable toincorporate an anchoring mechanism 220 into the cuff 102. The anchoringmechanism 220 can comprise any of a variety of anchors or barbs such asthose that have been used extensively on interventional devices, such asgrafts for the treatment of abdominal aortic aneurysms, atrial appendageclosure devices and filters. Most of the traditional retentionmechanisms used for percutaneously implantable valves rely on aninterference fit between the implant and the vessel to provide asignificant portion of the retention force, or to activate the retentionmeans. However, in the case of a replacement mitral or aortic valve, itcan be desirable to minimize the radial force at the valve annulus,because excessive dilation of either annulus may have a detrimentaleffect on the function of another other valve.

With reference to FIG. 26, the anchoring mechanism 220 generallycomprises a radially extending flange 222 that protrudes radiallyoutward from the implant 100 to engage the tissue thus securing theimplant 100 from migration. The radially extending flange 222 caninclude a sharpened tip 224 as shown in FIG. 26. With reference to theparticular embodiment shown in FIG. 26, the anchor 220 can comprise alooped base 226 that is coupled to the cuff 102 by sutures 228. The base226 can be sutured to a reinforced area 230 of the cuff 102. Of course,those of skill in the art will recognize in light of the disclosureherein various other configurations of the anchor 220 and the manner ofsecuring the anchor 220 to the implant 100.

In another embodiment, the valve 100 is sutured to the native anatomy.For example, the valve 100 can include a sewing ring configured allowsutures to be easily attached to the implant 100. A percutaneous orminimally invasive sewing device can also be incorporated or used as asecondary procedure. This device would contain at least one needleremotely actuated to attach the valve 100 to the tissue, or to a seconddevice previously implanted at the desired valve location. Other methodsmay utilize a balloon or other force mechanism to push or pull thesuture into position. These needles can be made from metallic or polymerelements or utilize sutures that may be inserted through the anatomy.They would range in diameters from 0.002 inches to about 0.040 inchesand may protrude into the anatomy from 0.005 inches to about 0.090inches depending upon the anatomy.

With reference to FIGS. 27A-C, in yet another embodiment, the valve 100is stapled or clipped into place with a single or multiple detachablestaples, clips, barbs or hooks. As shown in FIG. 27A, the valve 100 canbe positioned over the native aortic valve 24. In this embodiment, thevalve 100 is temporarily secured by control wires 230 as will beexplained in more detail below. A surgically inserted or percutaneouslyinsert tool 232 is positioned near the valve 100 and is used to insertclips 234 or other type of anchor around the annulus and allows them toengage the tissue and/or portion of the valve 100. The staples, clips,hooks or barbs could also be delivered percutaneously with a device thatpositions the staples, clips, hooks or barbs near or below to the nativevalve. These could be attached through a balloon, pull wire or otherforce mechanism to push or pull them into position. The tool 232 used tostapled in place the valve 100 can be similar to those used to connectthe mitral valve leaflets together by the company E-Valve and describedin US patent publication 2004/0087975 Lucatero, Sylvester et al, whichis hereby incorporated by reference herein. FIGS. 27D and 27E illustratean embodiment in which the tool 232 includes a tensioning wire 233,which has a distal end that is preferably coupled to the distal end ofthe device 232 and has a proximal end that extend through the device232. By applying tension to the wire 233, the top of the too 232 can bebent towards the wall of the aorta as shown in FIGS. 27D and 27E.

In one embodiment wires similar to, the control wires 230 described inthis application serve as guide wires over which the secondary anchoringcatheter is delivered. This allows the precise placement of the anchors,staples, sutures etc. relative to the prosthesis, because the anchorcatheter will follow the wire right to the desired anchor location. Inone embodiment the anchor location is at the valve commissures. Inanother embodiment the anchor location is at the proximal end of thedevice. The anchor delivery catheter may consist of a multi lumen tubewhere one lumen serves to track over the wire and the second lumen oradditional lumens deliver the anchor. In one embodiment the anchor is ascrew which is actuated with a rotational motion and threaded throughthe prosthesis and in to the aortic wall. Other anchor designs describedin this application may also be adapted to the anchor delivery catheter.

In another embodiment, an adhesive is used to secure the valve 100 tothe tissue. For example, adhesives such as a fibrin glue orcyanoacrylate could be delivered percutaneously or surgically to attachthe valve 100 to the tissue. A method for percutaneously delivering anadhesive includes channeling it through a tubular support member, whichhas openings around its outer surface to allow the adhesive to bereleased. The adhesive could be used in conjunction with other anchoringmethods to ensure that no blood leaks around the valve 100. Adhesionenhancing surfaces can be provided, such as ePTFE patches or jackets, topromote cellular in-growth for long term anchoring.

With reference to FIG. 28, in another embodiment, a barb, anchor, hookor pin 220 is located within a fold 110 of the cuff 102. When theinflation channels 120 are not inflated, the flange 222 of the anchor220 does not extend in a radial direction. As the inflation channels 120in the cuff 102 are inflated and deployed, the anchor 220 is configuredto unfold moving the flange 222 of the anchoring mechanism 220 into aradially protruding position. In such an embodiment, a section of thecuff 102 can be reinforced to inhibit the anchoring mechanism frompuncturing the fabric or inflation passages 120 of the cuff 102.Preferably, the anchoring mechanism 220 is located so that the sharp end224 of the anchor mechanism is designed to engage the tissue is notlocated near an inflation passage 120, and is oriented so that it isunlikely that the anchoring mechanism 220 could damage an inflationpassage during normal use of the device. The anchor mechanism 220 couldbe attached to the cuff 102 in many ways, for example the end of theanchor mechanism 220 not intended to engage tissue could be sutured,glued or crimped to the cuff. In this case the sutured end of the anchormechanism 220 can have a shape that prevents disengagement from thesutures. The anchor mechanism 220 may have holes through it, which thesutures pass through, or the anchor mechanism may be made from wire andshaped in a configuration that does not allow the disengagement of thesutures. One suitable pattern is a generally circle, or oval shape.Others would be apparent to one skilled in the art. FIG. 29 illustrateda modified embodiment in which the anchor mechanism is positioned on aninflatable strut. In yet another embodiment, the anchors 220 can befixed to the device at or near the attachment point of the deploymentcontrol wires 230 to provide a solid engagement for each anchor, and totest the engagement of each anchor individually.

In the embodiment of FIGS. 28 and 29, the anchor 220 can comprise alaser cut tubular member attached to the inflation lumens such that theydeploy and expand radially when inflated and provide an exposure to apoint or hook 224. These expansion members could be cut from stainlesssteel and be plastically deformable or a super-elastic material such asNitinol and recover as the inflation lumen is deflated thus hiding thepoint or hook from tissue exposure. It may be desirable to wrap thesedevices around the inflation lumen and attach them to the cuff forstability. A longer device may provide better stability since the forceswould be spread out over a longer distance. A single device or multiplehooks may be required to anchor the cuff properly. The hooks 224 may bepointed either proximally or distally or in both directions if desired.The hooks 224 in these embodiments would preferably be bent from theaxial direction between 40 and 95 degrees.

FIG. 28A illustrates an other embodiment of an anchor 224. In thisembodiment, the anchor is supported between a pair of annular stents 221that are formed with proximal and distal bends in a generally sinusoidalpattern. The stents 221 can be wrapped around an inflation lumen asshown. In one embodiment, the hook 224 is moved into a radiallyextending position as the stents 221 are expanded by the inflationlumen.

In another embodiment, the distal and proximal ends 128, 126 of theimplant 100 can be sized to provide an anchor functions For example, asdescribed above with reference to FIG. 3A, the valve 100 can utilize adistal or proximal ends 128, 126 of larger diameter than the middleportion 124 of the valve 100. In a preferred embodiment, the implant 100includes both an enlarged distal and an enlarged proximal ends 128, 126.This produces a device with an hourglass shape as shown in FIG. 2A. Theenlarged sections 128, 126 of the valve 100 inhibit the device frommigrating proximally or distally. It is also possible to shape thetransitions of the implant 100 so that the cone shape produces a wedgeeffect in a desired location, thereby increasing the radial force.Alternatively it is possible to shape the transitions with a shallowangle so that the implant is shaped like a rivet and the radial forcecaused by the application of axial force is minimized. The axial forceis applied to the implant by the pressure of the blood acting on thearea of the implant. This axial force must be reacted by a normal forceon the surface of the implant. The implant 100 can be designed so thatthe radial component of the normal force at any desired location is anydesired ratio of the axial force.

For an implant 100 that utilizes an hourglass shape as described above,the orientation of the anchoring mechanisms 220 described above can beadapted from radially expandable applications can be reevaluated andreapplied. For example barbs could be placed on the most distal portion128 of the hourglass shaped structure and the barbs would preferably beoriented approximately parallel to the axial direction. See e.g., FigureFIG. 28. During the deployment procedure, the implant can be pulled backinto the annulus after the distal portion 128 inflated. An axial forceis then applied by the inflation lumens 120 to the anchoring mechanism220.

FIG. 30 illustrates an embodiment of an actuated anchoring mechanism240. In this embodiment, a rod member 242 is coaxially positioned withina tube 244 positioned generally on the outer surface of the valve 100. Aradially extending hook or barb 246 is attached to the rod member 242and extends through a slot 248 formed in the tube 244. In a firstposition, the barb 246 extends generally against the outer surface ofthe valve 100. When the rod 242 is rotated, the barb 246 rotates awayfrom the valve 100 to expose the barb 246 and form an anchor. Whenrotated back, the barb 246 would unexposed such that the valve 100 canbe delivered or repositioned. In the illustrated embodiment, the rodmember 242 is coupled to the control wire 230. The slot 248 forms a rampor guide that promotes rotational movement and exposure of the barb 246as the rod member 242 is axially moved within the tub 246. The mechanismcould also be driven hydraulically by the inflation of the device.

FIG. 30A illustrates another embodiment of an actuated anchor mechanism240. In this embodiment, the mechanism 240 comprises a proximal tubeportion 250 and a distal tube portion 252, which interface atcorresponding tapered faces 254 a, 254 b. By applying a force to the twosections of tube, the distal portion 252 moves both longitudinally andhorizontally exposing a sharp section 256 of the lower portion 252 tothe tissue wall. Once exposed and engaged to the wall of the tissue, thedevice could be locked by maintaining a force on control wire 230 or byusing an interference fit such as a screw and nut to hold the device inplace.

FIG. 31 illustrates another embodiment of an actuated anchoringmechanism 240. In this embodiment, the anchor 240 comprises a tubularmember 260, with a pattern 262 cut into the tubular member 260. Thecontrol wire 230 extends through the tubular member 260 and is attachedto a distal stop 264. The tubular member 260 is attached to the cuff 102by sutures, adhesives etc. By pulling on the control wire 230,longitudinal compression forces cause the tube to buckle exposes a hookor barb 266 to the tissue wall. The tube 260 may be made from a metallicmaterial such as stainless steel or Nitinol. If the tube 260 issuper-elastic it can be possible to recover the hook 266 when the forceis released. If made from a stainless steel or the like, the anchor 240can be plastically deformed and the exposure of the hook 266 would beset. The actuation of this anchor 240 generally requires a longitudinalforce to buckle the tube 260 and may require a lock to hold the tensionin the pull wire 230. This lock could be maintained by an interferencefit such as a screw and nut.

In this embodiment, the hook 266 can be cut from a hypotube 260 ofslightly larger inside diameter than the deployment control wire 230outside diameter. Preferably these diameters are in the range of 0.01 to0.03 inch. The hook 266 preferably extends from the device at an angleof 10 to 80 degrees, more preferably at an angle of 20 to 45 degrees.

FIG. 32 illustrates another embodiment of an actuating anchor mechanism240. In this embodiment, the anchor 240 comprises a pre-shaped finger270 that was cut into a tube 272 and formed such that it would bendthrough the tubes inner diameter 274 and expose a point on the oppositeside of the tube. A window 276 cut through both walls of the tube 272would allow for this exposure of the hook 270. A wire 230 can be placedthrough the tube 272 to would interfere with the hook to hide it fordelivery and recovery. This pivoting hook 272 could also be used on thesame wall side if the attachment to the tube was in the center of thehook 272. Similar locking devices for the wire could be used ifnecessary described above. In the illustrated embodiment, the tube 272includes slots 278 cut into the wall of the tube 272 to enhance theflexibility of the tube 272.

FIG. 32A illustrates yet another embodiment of an actuating anchormechanism 240 a. In this embodiment, the anchor 240 a also comprises apre-shaped finger 270 a that was cut into a tube 272 a and formed suchthat it would a first end 273 a bend through the tube's inner diameter274 a and expose a point 273 b on the opposite side of the tube 272 a. Awindow 276 a cut through both walls of the tube 272 a would allow forthis exposure of the hook 270 a. A wire 230 can be placed through thetube 272 to would interfere with the side 272 a of the hook 270 todeflect the point 273 b for delivery and recovery.

FIG. 33 illustrates another embodiment of an actuating anchor 240. Inthis embodiment, a tubular member 280 is attached to the cuff 102. Acoaxial member 282 (e.g., a distal end of the control wire 230) ispositioned within the tubular member 280 and provided with a hook 284that can be attached or integral to the coaxial member 282. When thecoaxial member 282 is moved longitudinally within the tubular member 280the hook 284 is exposed through a window or opening 286 in the tube 280.If pre-shaped Nitinol is used the hook 284 can be recoverable and hiddenback into the tube 280 for removal. The hook 284 can face eitherproximal or distally or both directions for device stability.

Delivery Catheter

FIGS. 34-37 illustrate an exemplary embodiment of a delivery catheter300 that can be used to deliver the valve 100 describe above. Ingeneral, the delivery catheter 300 can be constructed with extrudedtubing using well known techniques in the industry. In some embodiments,the catheter 300 can incorporates braided or coiled wires and or ribbonsinto the tubing for providing stiffness and rotational torqueability.Stiffening wires may number between 1 and 64. More preferably, a braidedconfiguration is used that comprises between 8 and 32 wires or ribbon.If wires are used the diameter can range from about 0.0005 inches toabout 0.0070 inches. If a ribbon is used the thickness is preferablyless than the width, and ribbon thicknesses may range from about 0.0005inches to about 0.0070 inches while the widths may range from about0.0010 inches to about 0.0100 inches. In another embodiment, a coil isused as a stiffening member. The coil can comprise between 1 and 8 wiresor ribbons that are wrapped around the circumference of the tube andembedded into the tube. The wires may be wound so that they are parallelto one another and in the curved plane of the surface of the tube, ormultiple wires may be wrapped in opposing directions in separate layers.The dimensions of the wires or ribbons used for a coil can be similar tothe dimensions used for a braid.

With initial reference to FIG. 34, the catheter 300 generally comprisesan outer tubular member 301 having a proximal end 302 and distal end 304and an inner tubular member 305 also having a proximal end 303 and adistal end 307. The inner tubular member 305 extends generally throughthe outer tubular member 301, such that the proximal and distal ends303, 307 of the inner tubular member 305 extend generally past theproximal end and distal ends 302, 304 of the outer tubular member 301.The proximal end 303 of the inner tubular member 305 includes aconnection hub or handle 306 to mate other lab tools and to grasp andmove the inner member 305 with respect to the outer member. A hemostasisvalve 308 is preferably provided between the inner and outer members301, 305 at the proximal end 302 of the outer tubular member 301. Astrain relief 313 is preferably provided between the inner tubularmember 305 and the handle 306 to limit strain on the inner member 305.The proximal end 302 of the outer tubular member 301 can include agrasping member or handle (not shown) for holding the outer tubularmember 301 stationary with respect to the inner tubular member 305.

In one embodiment, the outer diameter of the catheter 300 measuresgenerally about 0.030 inches to 0.200 inches with a wall thickness ofthe outer tubular member 301 being about 0.005 inches to about 0.060inches. In another embodiment, the outer diameter ranges from about 0.15inches to about 0.35 inches or from about 12 French to about 27 French.In this embodiment, the wall thickness of the outer tube 301 is betweenabout 0.005 inches and about 0.030 inches. The overall length of thecatheter 300 ranges from about 80 centimeters to about 320 centimeters.

As mentioned above, the catheter 300 includes a connection hub or handle306 that is configured to allow wires, devices and fluid to pass as willbe explained in more detail below. The connection hub 306 is preferablycompatible with normal cath-lab components and can utilize a threadedend and a taper fit to maintain seal integrity. The inner diameter ofthe inner member 305 of the catheter 300 is configured allow for coaxialuse to pass items such as guidewires, devices, contrast and othercatheters. An inner lining material such as Teflon may be used to reducefriction and improve performance in tortuous curves. Additionally,slippery coatings such as DOW 360, MDX silicone or a hydrophilic coatingfrom BSI Corporation may be added to provide another form of frictionreducing elements.

Multidurometer materials in the catheter 300 can help to soften thetransition zones and add correct stiffness for pushability. Transitionzones may also be achieved through an extrusion process know as bumptubing, where the material inner and outer diameter change during theextrusion process. The entire catheter shafts 301, 305 can be producedin one piece. Another method for producing such a catheter shaft is tobond separate pieces of tubing together by melting or gluing the twocomponents together and forming a single tube with multiple diametersand or stiffness. The application of heat can be applied by laser orheated air that flows over the shaft material or other methods of heatapplication sufficient to flow the materials together.

With continued reference to FIG. 34, the distal end 304 of the outersheath 301 comprises an enlarged diameter section 309, which isconfigured to cover the implant 100. In one embodiment, the diameter ofthe enlarged diameter section 309 where the implant 100 is contained isbetween about 0.20 inches and about 0.32 inches in diameter with alength between about 0.5 in and about 5.0 inches. A second portion 310of reduced diameter and increased flexibility is located proximal to thesection 309 that covers the implant 100. This section ranges from about0.10 inches to about 0.25 inches in diameter. In the preferredembodiment, the distal section 309 is about 0.29 inches diameter, andabout 0.08 inches in length and the proximal section 310 has an outsidediameter of about 0.19 inches. The enlarged distal portion 309 can bemade from a material with a higher durometer than the proximal portion310 of the catheter 300. In one embodiment, the material of the enlargeddistal portion 309 is a biocompatible material. In another embodiment,the material is a metallic material such as stainless steel. In anotherembodiment, the material is a polymer such as FEP, PEEK or a polyimide.In another embodiment, the enlarged distal portion 309 of the devicewhich covers the implant 100 is capable of transmitting light in thevisible spectrum. This allows the orientation of the implant 100 to bevisualized within the catheter 300. The distal end 304 may have aradiopaque marker (not shown) to locate the catheter 300 underfluoroscopy.

With continued reference to FIGS. 34-37 and in particular FIGS. 36A and36B, multiple tubes extend through the inner member 305. Specifically,in illustrated embodiment, a guidewire tube 318, two inflation tubes 320and three control wire tubes 316 extend from the proximal end 303 to thedistal end 307 of the inner member 307. Of course, in modifiedembodiments, various other numbers and combinations of tubes 316, 318,320 can be used depending upon the configuration of the implant 100 andthe deployment procedure. These tubes may be extruded from materialssuch as polyethene, polypropylene, nylon, PEEK, polyimide or otheraccepted polymer materials. They may also combine metallic elements suchas coils or braids for additional support or be made from metallictubings such as Nitinol or stainless steel. As will be explained below,the guidewire tube 318 is configured to receive a guidewire. Theinflation tubes 320 are configured to delivery inflation media to theimplant 100 and the control wire tubes 316 receive the control wires230, which are coupled to the implant 100. As will be explained in moredetail below, the inflation tubes 320 can include inner and outermembers 320 a, 320 b (see FIG. 36B) for providing an inflationdisconnect mechanism as described below with reference to FIGS. 40A and40B.

The inner member 305 material may also consist of stiffening members fortransition zones or bump extrusions to reduced diameter and maintaincorrect pushability. Conventional guidewire passage through the cathetersuch as “over-the-wire” may be used or technology such as“rapid-exchange” may aid in procedure ease and catheter exchanges. Sincemultiple devices may be placed in a single catheterization,rapid-exchange may be preferred but not essential. Other features thatmay aid in ease of use include a slippery coating on the outer and orinner diameter such as mineral oil, MDX (silicone) or a hydrophiliclayer to allow easy access to tortuous anatomy, or easier morecontrolled motion of one portion of the catheter relative to anotherportion of the catheter. It may be necessary or desirable to utilize aballoon to initiate radial contact of the device to its final positionand location. In one embodiment, an inflation lumen and balloon placeddistal to the hubis used. This balloon is used to pre-dilate the nativevalve annulus, vessel or ostium where the valve may be implanted.Elements to transmit signals externally could be imbedded into thecatheter 300 for pressure and flow readings or Doppler information.These may include electro-mechanical sensors, such as piezo-electricdevices, electrical sensors, wires, pressure portal or lumens or opticalfibers.

As mentioned above, delivery of the implant 100 via catheterization ofthe implantation site can include a mechanism to deploy or expel theimplant 100 into the vessel. This mechanism may include a push or pullmember to transmit forces to the distal portion of the catheter 300.These forces may be applied externally to the body and utilize a handleat the proximal end of the catheter. Devices to transmit forces to thedistal end may also include a rotational member to loosen or tighten,convert a torque into a translational force such as a threaded screw andnut or to add or subtract stiffness to the catheter or device, or tocause the device to assume a specific shape. The handle mechanism mayalso include a port for hydraulic pressures to be transmitted to thedistal portion of the catheter or have the ability to generate hydraulicforces directly with the handle. These forces may include a pushing orpulling transmitted to the device or catheter, an exposure of the deviceto allow for implantation or to expel the device from the catheter.Further forces may include a radial or longitudinal expansion of thedevice or catheter to implant or size the location of implantation. Thehandle may also include connections to electrical signals to monitorinformation such as pressures, flow rates, temperature and Dopplerinformation.

With reference to FIGS. 34 and 36, in the illustrated embodiment, theimplant 100 is loaded between the distal portion 309 of the outer sheath301 and the inner sheath 305. The distal portion 309 therefore forms areceptacle for the implant 100. A distal tip 312 can be coupled to theguidewire tube 318. The tip 312 can be used to close the receptacle whenthe catheter 300 is being advanced. The tip 312 can be distanced fromthe outer sheath 301 by proximally retracting the outer sheath 301,while holding the guidewire tube 318 stationary. Alternatively, theguidewire tube 318 can be advanced while holding the outer sheath 301stationary. Control wires 230, which extend through the control wiretubes 316, can be coupled to implant 100 as described below and used tohold the implant 100 stationary as the implant outer sheath 301 isretracted. Alternatively the outer sheath 301 can be retracted withrespect to the inner sheath 305, which acts as a pusher to push theimplant 110 outer of the distal portion 309 of the outer sheath. Theinflation channels 120 of the implant 100 are preferably connected tothe inflation tubes 318 of the catheter by an inflation connectionmembers 321 as will be described in more detail below.

With continued reference to FIG. 36, the inflation tubes 318, guidewiretube 320 and control wire tube 316 preferably extend to the proximal end303 of the inner member 305. A connection hub 323 can be provided forconnecting an inflation fluid source to the inflation tube 318. Variouscontrol mechanism (not shown) and sealing devices can also be providedfor connecting to the control wires 230 and control wire tubes 316.

As will be described in more detail below, the control wires 230 and/orinflation lumen 318 can form part of a deployment mechanism for theimplant 100. As the implant is navigated to the site, attachment betweenthe implant 100 and catheter 300 is important. Many detachmentmechanisms have been used to deploy devices such as stents and emboliccoils through balloon expansion and simple pushable coils expelled fromthe distal end of a catheter. The implant 100 can utilize many differentmethods to implant 100 at the selected site such as an expulsion out theend of the catheter, a mechanical release mechanism such as a pin joint,unscrewing the device from the catheter delivery system, a tethered linksuch as a thread or wire, a fusible link as used in a GDC coildeployment, a cutting tool to sever a attachment of the device from thecatheter, a threaded knot to tether the catheter to the device where theas the knot could be untied or cut, a hydraulic mechanism to deploy,expand or fracture a link between the catheter and the device. All abovementioned concepts can be enhanced by the utilization of the flexibletip 312 to allow acute articulation of the device and delivery catheter300 to gain access to the implantation site.

As will be explained in more detail below, after the implant 100 hasbeen temporarily deployed or positioned, it may be advantageous torecapture or reposition the implant for optimal results. This mayinclude a rotation or translation of the implant 100 or a completeremoval and exchange for a different diameter, length or style device.Capture of an implanted device may require a second catheter to reengagethe device to remove or reposition to a proper location. This cathetermay be constructed from polymer tubing as described above includingcoils, braids, etc. Additionally there may be a braided section at thedistal most portion of the catheter to accept or capture the device forretrieval from the body.

As mentioned above, the guidewire tube 320 preferably extends throughthe inner sheath 305 and the tip 312. The guidewire tube 320 may have aninside diameter of 0.035 to 0.042 in so that the device is compatiblewith common 0.035 or 0.038 guide wires. A modified embodiment includes alumen 0.014 to 0.017 inches in diameter for compatibility with 0.014 indiameter guide wires. In a third embodiment, the guidewire lumen 320 is0.039 to 0.080 in diameter, so that the device may be delivered over alarger than standard guide wire, or a diagnostic catheter, such as a pigtail catheter. This provides the advantage of a stiffer support tofacilitate easier delivery through calcified valves. If a diagnosticcatheter is used as a guidewire it may also serve as a port for contrastinjection.

The guidewire tube 320 can be made from a lubricious material such asTeflon, polypropylene or a polymer impregnated with Teflon. It may alsobe coated with a lubricious or hydrophilic coating. The tube 320 can beconstructed of multiple layers of material, including a lubricious innerlayer and an outer layer to facilitate bonding to other cathetercomponents.

The catheter 300 may be delivered over a guide wire to aid inpositioning. The guide wire may pass coaxially through the entire lengthof the catheter or in modified embodiments may pass coaxially thoughonly a portion of the catheter in a configuration known as rapidexchange. This allows shorter guide wires to be used if devices are tobe exchanged out.

In the illustrated embodiment, the catheter 300 comprises the outercatheter shaft 301 and the inner catheter shaft 305 which move relativeto one another. In order to minimize the risk of guidewire damage in arapid exchange design where the catheter must pass through the wall oftwo sheaths which move relative to one another, a slot feature isdesirable. Either the inner or outer elongate tube may contain alongitudinal slot in the area where the guide wire passes from the innerdiameter to the outer diameter of the catheter assembly. The otherelongate tube preferably contains a hollow pin to engage the slot andprevent the excessive movement of the two elongate members. The guidewire passes through the opening in the hollow pin. The inner diameter ofthe hollow pin is preferably oriented at an acute angle to the centralaxis of the catheter.

Another design to enable rapid exchange like performance is for theguide wire to enter the catheter tip through a side hole distal to thelocation of the prosthetic valve. The guidewire exits the tip of thesystem near the center of the catheter tip. This design enables thecatheter to follow the guide wire across the native valve, while stillallowing multiple devices to be exchanged easily on a short length guidewire.

As described above, the internal lumens of the catheter 300 can includethe deployment control wires lumens 316, the inflation lumens 320, andan inner sheath 307 that encapsulates these lumens 316, 320. See e.g.,FIG. 36B. With reference to FIG. 37A, in one embodiment of the deliverysystem 300, a portion of, or all, of the internal lumens 316, 320 arelocated within the delivery catheter 300 at the distal portion 304 ofthe catheter, and pass through a hole 650 in for example a middleportion 652 of the delivery catheter 300 so that they are locatedgenerally parallel to the delivery catheter 300 at the proximal end 306of the catheter 300. In one embodiment, the hole through 650 which thelumens 316, 320 pass can be located between about 2 and about 20 cm fromthe distal end 304 of the device 300. The outside diameter of thedelivery catheter 300 is substantially reduced proximal to the hole asshown in FIG. 37A, so that the entire device 300 may pass through mostcommon introducers that are large enough to accept the distal portion304 of the device 300.

This catheter configuration advantageously allows the operator to easilyswitch between the delivery sheath 300 and a recovery sheath (describedherein) in the event that the device 100 needs to be recovered, becausethe delivery sheath 300 can be retracted out of the body over relativelyshort internal lumens 316, 320, while still maintaining a portion of thelumens 316, 320 outside the catheter so that the operator can manipulatethem as necessary.

Because of its shorter length the recovery sheath may not require theexchange hole 650, and it may be possible to locate the internal lumenscoaxially within the recovery sheath. However in the preferredembodiment the recovery sheath also includes a hole in a similarlocation allowing the internal lumens to pass coaxially through thedistal portion of the sheath, through the hole, and be located generallyparallel to the recovery sheath in the proximal portion.

In one embodiment contrast media is passed through a lumen (e.g., theguidewire tube 320) of the device, and the lumen passes through theprosthetic valve 100. This allows visual evaluation of valve function byangiography, without crossing the valve with an additional device. Inthe preferred embodiment the lumen crosses the valve while the valve isin the catheter. In the preferred embodiment the lumen also serves asthe guidewire tube 320, where the device is delivered over a guide wire.The wire may be removed from the lumen to allow more cross sectionalarea for contrast injection. The proximal end of the lumen near thehandle of the device attaches to a fitting to allow the injection ofcontrast media with a power injector tool. The inner diameter of thelumen may range from 0.014 to 0.100 inch. The diameter of the lumen mayvary along the length of the catheter, for example, Preferably theportion of the lumen which passes through the prosthetic valve is of aminimum possible diameter to allow both sufficient flow and the use ofan adequate sized guidewire. This portion is preferably in the range ofdiameters from 0.014 to 0.080. The portion of the lumen extending alongthe length of the catheter proximal to the implant may be of largerdiameter, the larger diameter allows flow of contrast media at lowerpressure gradients, and the corresponding larger outside diameter doesnot increase the profile of the complete device. This portion of thelumen is preferably in the inside diameter range of 0.035 to 0.100 in.The distal portion of the lumen may contain a diffuser or transition toa larger diameter to minimize the pressure required to inject asufficient volume of contrast media through the lumen. Multiple exitports positioned around a nose cone also facilitate the flow of contrastmedia.

Access for the catheter 300 may be gained through a major artery such asthe femoral artery. This access site is particularly appropriate foraortic valve replacement. Alternative access methods may be bettersuited for other valves. For example the tricuspid valve and possiblythe pulmonary valve could best be accessed through the venous system. Inthis case, access would be gained through either a femoral vein or ajugular vein. The catheter would then be passed into the right atriumthrough the superior or inferior vena cava. Some embodiment of thecurrent invention utilize a relatively large diameter catheter, whichmay not be compatable with the diameter of all patients femoralarteries. In these patients it may be desirable to access the commoniliac artery or to use a transeptal approach and access the heartthrough the venous system.

As mentioned above, the catheter 300 includes an atraumatic tip 312 toallow the device to be easily placed through the hemostasis valve of theintroducer, and to easily cross the calcified aortic valve. The tip 312may be cone shaped bullet shaped or hemispherical on the front end. Thelargest diameter of the tip 312 is preferably approximately the same asthe distal portion 309 of the outer sheath 301. The tip 312 preferablysteps down to a diameter slightly smaller than the inside diameter ofthe distal portion 309 of the outer sheath 301, so that the tip canengage the outer sheath 301 and provide a smooth transition. In theillustrated embodiment, the tip 312 is connected to the guide wire tube320, and the guide wire lumen passes through a portion of the tip 312.The proximal side of the tip 312 also has a cone, bullet orhemispherical shape, so that the tip can easily be retraced back acrossthe deployed valve 100, and into the deployment catheter 300. The tip312 can be manufactured from a rigid polymer such as polycarbonate, orfrom a lower durometer material that allows flexibility, such assilicone. Alternatively, the tip 312 may be made from multiple materialswith different durometers. For example, the portion of the tip 312 thatengages the distal portion 309 of the outer sheath 301 can bemanufactured from a rigid material, while the distal and or proximalends of the tip are manufactured from a lower durmoter material.

With reference to FIGS. 35A and 35B, in a modified embodiment, the areawhere the tip 312 of the device is located to house a balloon 312 a fordilatation. This balloon 312 a could use the lumen where a guidewirepasses through (as shown in the illustrated embodiment) or a separatelumen for inflation and deflation. Since the distal portion 309 israther large (10-24 French) it can be advantageous place to locate alarge diameter balloon that could be used to pre or post dilate thevalve area. There may also be a stent or other structure mounted to thisballoon 312 a for device securement or anchor deployment. The balloon312 a could also be covered with a thin membrane material similar to the“SOX” device commercialized by Boston Scientific and seen in U.S. Pat.No. 6,280,412 Pederson Jr. et al. This covering would allow the deviceto be hidden during delivery and could be exposed when inflated. Inanother embodiment, a tear-away sheath that covered the balloon 312 afor protection can be used.

FIGS. 38A-38C illustrate one embodiment of a retractable sheath 340 thatmay be used in combination with the deployment catheter 300 describedabove. Many implantable medical devices have been delivered usingretractable sheaths. For example, some devices include self-expandingstents, and grafts to percutaneously treat abdominal aortic aneurysms.On problem with this design is that the catheter must slide over theimplant, resulting in a scraping and shear forces. For a delicateimplant such as a tissue valve or abdominal aortic aneurism graft, thisscraping or shearing may result in damage to the implant. In lessfragile devices such as self-expanding stents the sheath material may bescraped off and embolized. Several medical devices have solved thisproblem using a radially expandable shear barrier, as described byChobotov. This shear barrier in practice typically consists of a thinwalled piece of tubing, slit along its length in several places. As theouter sheath is retracted, it slides along the slit tubing. Once theouter sheath has retracted past the slit tubing, it can expand radiallyallowing the device to be released.

The retractable sheath 340 of FIGS. 38A-C serves a similar function tothe radially expandable shear barrier describe above, but providesseveral advantages. For example, as explained below, it does not havesharp edges and it can be made from a softer material, so it is lesslikely to cause trauma to the patient, or damage to the implant. Inaddition, it can be made from a thinner material allowing the device 340to have a lower profile. And it does not protrude the full length of theimplant 100 after the outer sheath 340 has been retracted.

As shown in FIGS. 38A-C, in the illustrated embodiment, the catheter 300the outer sheath 301 is retracted to deploy the implant 100 and theinner sheath 305, which is stationary relative to the outer sheath 301,acts as a pusher and prevents the implant 100 from moving back with theouter sheath 301 during deployment. A thin flexible membrane 340connects to the outer surface 342 of the pusher 305 and passes betweenthe implant 100 and the outer sheath 301 and acts as a shear barrier.The flexible shear barrier 340 then attaches to the outer distal end 344of the outer sheath 301. Preferably the membrane or shear barrier 340extends out the tip of the outer sheath 301 and then is pulled insideout over the outer sheath 301 as shown in FIG. 28A. The membrane orshear barrier 340 is then bonded to the outer sheath 301 on its outersurface 342 near the tip of the outer sheath 301. In a modifiedembodiment, the flexible shear barrier 340 is bonded to the innersurface 346 of the outer sheath 301. The shear barrier 340 is preferablymade from a polymer and has a thickness of about 0.0002 inches to about0.0020 inches. In one embodiment, the polymer is nylon. The shearbarrier 340 can be manufactured by an extrusion process or by a balloonblowing process where a polymer tubing is inflated inside a mold usingheat and pressure.

As shown in FIGS. 38B and 38C, as the outer sheath 301 is pulled backthe membrane 340 turns inside out and retracts from the implant 100,doubling over on its self. The sliding occurs between the flexiblemembrane 340 and the inner surface 346 of the outer, retractable sheath301. Advantageously, little or no relative motion occurs between theimplant 100 and the portion of the membrane 340 in contact with theimplant 100. This minimizes any potential damage to the implant 100, andthe risk of embolizing particles from the sheath 301. A lubricant can beapplied between the outer sheath 301 and the membrane 340 and betweenthe outer sheath 301 and the pusher 305. The membrane 340 advantageouslyserves to isolate the implant 100 and the patient from the lubricant.This embodiment reduces the force necessary to deploy the implant 100,and allows for a smoother more controlled deployment.

With reference back to FIG. 34, the hemostasis valve 308 is preferablyis attached to the proximal end of the outer sheath 301 to prevent bloodfrom leaking past the inner and outer sheaths 301, 305. In oneembodiment, the valve 308 is a touhy-borscht design valve, or similarvalve where the radial compression is easily adjustable. By adjustingthe valve it is possible to lock the outer sheath 301 to the innersheath 305 of the catheter 300 to prevent their accidental relativemotion during delivery of the implant. At the proximal end 304 of thecatheter 300, an additional hemostasis valve (not shown) is preferablyprovided to provide a seal for the multiple inflation lumens, anddeployment control wires that must pass through the inner sheath 305. Anadditional port (not shown) can also be provided to allow the catheter300 to be flushed to remove any trapped air before the catheter 300 isinserted into the patient.

Connection Between Implant and Inflation Lumens

As described above, in many embodiments, the implant 100 includes aninflatable structure 107, which defines inflation channels 120. In theseembodiments, the inflation channels 120 are inflated with inflationmedia 122 to provide structure to the implant 100. As shown in FIGS.34-37, the deployment catheter 300 includes at least one inflation tube318 and in the illustrated embodiment two inflation tubes 318 thatextend through from the proximal end 304 to the distal end of 302 of thecatheter 300. The inflation tubes are placed in communication with theinflation channels 120 such that inflation media 122 can be supplied tothe inflatable structure 107. It will be appreciated that after theinflatable structure 107 is inflated the inflation tubes 318 will needto be disconnected or uncoupled from the implant 100. Various devicesand methods for uncoupling the implant 100 from the inflation tubes 318will now be described.

In general, in embodiments in which the inflation media 122 is not selfsealing the inflation channels 122 will need to be sealed as theinflation lumen 318 is disconnected from the implant 100. Sealing ofthese lumens could utilize many different techniques known to oneskilled in the art. For example, as explained below, the inflation lumencan be placed through a valve, in such a way that it forces the valveinto the open position. The valve could be one of a variety of normallyclosed or one way (check) valves.

For example, FIG. 39A illustrates an embodiment of a connectionmechanism 350 that includes a check valve 352 comprising a spring 354and a ball member 356. The spring 354 and ball member 356 are positionedwithin a chamber 358 having a first open end 360 that is incommunication with the inflation channels 120 and a second open end 362that is in communication with the inflation tube 318. The spring 354 issupported by a narrowed portion 364 of the first open end 360. Thespring 354 biases the ball 356 against a valve seat 366 formed by thesecond end 362 of the chamber 358. In the biased closed position, theball 356 prevents inflation media 122 from exiting the inflationchannels 120. When inflation media 122 is applied under pressure to theinflation channels 120, the pressure pushes the ball away from the valveseat 366 and into the chamber 358 allowing inflation media 122 to flowinto the inflation channels 120. When the pressure is removed, thespring 354 forces the ball 356 against the valve seat 366 to prevent theinflation media 122 from escaping. A pin 368 can extend through theinflation lumen 318 and can be used to push against the ball 356,disabling the check valve 352 and allowing deflation of the inflationchannels 120.

FIG. 39B illustrates another embodiment of a check valve 352. In thisembodiment, check valve 352 comprises a duck-bill valve that includes atleast two flanges or bills 370 a, 370 b that are biased towards eachother to close the inflation channel 120. As with the ball valvedescribed above, a pin 368 can be used to open the valve 325 and allowdeflation of the inflation channels 120.

FIG. 39C illustrates another embodiment of a sealing mechanism 350. Inthis embodiment, the inflation lumens 120 are inflated using a needle(not shown) placed through a soft polymer plug 372 positioned betweenthe inflation lumen 318 and the inflation channels 120. The needle iswithdrawn from the plug 372 and the plug closes the hole formed by theneedle, preventing the loss of fluid or pressure. In the preferredembodiment the plug 372 is silicone inside a nylon, PE or PET tube 374.After the silicone is cured and bonded to the tube the tube mayoptionally be necked 376 to place a compressive force on the siliconeplug 372. The proximal and distal sections of the tube surrounding tothe plug can be necked to an even smaller diameter, to prevent themigration of the plug. The diameter of the needle may range from 0.010to 0.050 in with a diameter of about 0.020 in as the currently preferreddiameter. The plug 372 diameter may range from 0.020 to 0.120 in. In theillustrated embodiment, the plug 372 also includes an enlarged distalsection 376, which abuts against a distally facing ledge 378 providedwithin the tube 374 to secure the axial position of the plug 272. Theproximal end 280 of the plug 372 can have an outward taper as shown tofurther secure the plug 372 within the tube 374.

FIG. 39D illustrates another embodiment in which the connectionmechanism comprises a rupture disk 375, which is secured within aninside surface of a fluid tight chamber 377. The disk 375 is configuredto rupture and allow the inflation of the inflation channels 120 whensufficient pressure is applied.

In some embodiments, it is advantageous to configure the deploymentcatheter 300 and the implant 100 such that the inflation tube 318 cannotdisconnected unintentionally. For example, in one embodiment, theinflation tube 318 is connected to a deployment control wire 230 so thatthe inflation lumen 218 can not be removed from the implant 100 unlessthe deployment control wire 230 is also disconnected from the implant100.

FIGS. 40A and 40B illustrates one embodiment of sealing and connectionmechanism 399. In this embodiment, the balloon 111 is connected to apiece of tubing 400. Within the tubing 400, is positioned a seal-sealingplug 402, which can be configured as described above with reference toFIG. 39C. A tip 404 of the inflation lumen 318 is configured to beinserted through the plug 402 such that inflation media can be injectedinto the balloon 111. A connection balloon 406 is positioned generallyaround the tip 404 and proximally to the plug 402 within the tubing 400A fluid channel 408 connects the connection balloon 406 to an inflationport 410 on the proximal end of the catheter 300. In use, the balloon 11is inflated with inflation media provided through the tip 404. Todisconnect the inflation lumen 318 from the tubing 400, the connectionballoon 406 is deflated as shown in FIG. 40B allowing the inflationlumen 318 to be withdrawn with respect to the plug 402 and tubing 400. Astop or narrowed region (not shown) can be provided within the tubing400 to enhance the connection between the inflated connection balloon406 and tubing 400.

FIG. 41 illustrates another embodiment of sealing and connectionmechanism 399. In this embodiment, the mechanism 399 comprises a balland spring type check valve 412, which can be arranged as describedabove with the connection portion 351 of the balloon 111. A connectionmechanism 416 comprises an outer layer 418 and inner layer 420 ofcoaxial tubes. The inner layer 418 includes an engagement feature suchas a bump 422 that engages a corresponding engagement feature 424 on anouter surface 426 of the balloon 111 or other portion of the implant100. As shown in FIG. 41, the outer layer 418 extends over theengagement features 424, 426. The outer layer 418 is provided with adiameter that it forces the engagement feature 422 on the inner layer420 to remain engaged in the engagement feature 424 on the balloon 411.As the outer layer 418 is retracted, the inner layer 410 in the area ofthe feature 422 is free to disengage from the engagement feature 424 onthe balloon 422. In the illustrated embodiment, the inner layer 420defines in part the inflation lumen 318. A push wire 368 can be providedas described above for deactivating the ball valve 414 and allowingdeflation of the balloon 111.

FIG. 42 illustrates another embodiment of a sealing and connectionmechanism 399. In this embodiment, the mechanism 250 comprises a duckvalve 430 positioned in a connection portion 351 of the balloon 111.When the catheter 300 is engaged, the delivery tube 318 extends throughthe duckbill valve 420 allowing both inflation and deflation of theballoon 11. The tube 318 that extends through the valve 420 also extendsthrough a lock mechanism 432, which holds the inflation lumen attachedto the balloon. In the illustrated embodiment, the lock mechanism 432comprises of a lock tubing 434 that extends approximately the length ofthe catheter 3000. The distal end of the lock tubing 434 has an enlargedridge 436, and longitudinal slits 438 extending through the ridge 426.The distal end of the lock tubing 424 fits in an orifice plug 440, whichis inserted into the connection portion 351 of the balloon 111 in linewith the duckbill type valve 430. The orifice has a groove recess 442 toreceive the enlarged ridge 436 of the lock tubing 434. The longitudinalslits 438 in the lock tubing 434 allow it to collapse sufficiently toeasily engage and disengage from the groove 442 and the orifice 440. Theinflation tube 318 extends through the lock tubing 434 preventing itfrom collapsing and releasing from the balloon 111.

After the balloon 111 has been inflated with the desired inflation mediaand the operator has chosen to disconnect the catheter 300 from theimplant 100, the inflation tube 318 is withdrawn past the duckbill valve430. At this time suction may be applied to remove as much inflationmaterial as possible from the area past the valve 430. A rinse procedurecould also be used to remove additional fluid. The inflation tube 318 isthen withdrawn past the enlarged ridge 436 and the slit portion of thelock tubing 434. The lock tubing 434 can then be withdrawn from theorifice 440, and the implant 100 is separated from the catheter 300.

FIG. 43 illustrates another embodiment of a sealing and connectionmechanism 399. In this embodiment, connection portion 351 of the balloon111 comprises a threaded bore 448 and a valve seat 450 positionedgenerally proximally of the threaded bore 448 within a fluid channel452. A threaded portion 454 of a screw 456 is positioned within the bore448. An enlarged, sealing portion 457 of the screw 456 is positionedwithin the fluid channel 452 proximal to the valve seat 450. As thescrew 456 is threaded into the bore 448, the head 457 engages the seat450 to seal the fluid channel 452 formed in the connection portion 351.The delivery or connection tube 318 includes a distal end 460 that canbe inserted into the connection portion 351 of the balloon 111 to placethe delivery lumen 318 in communication with the fluid channel 352. Thedistal end 460 can be provided with releasable tangs 462 that engage acorresponding groove 464 formed on the inner surface of the connectionportion 351. The screw 458 is activated by a driver 466 that extendsthrough the inflation tube 318 as shown in FIG. 43.

Control Wires

As discussed previously above, one advantage of many of the embodimentsdescribed herein is that the deployment of the implant 100 can becontrolled. In one embodiment, the deployment of the implant iscontrolled via the use of control wires 230 that can be detachablycoupled to the implant. Various mechanisms for detachably coupling thecontrol wires 230 to the implant 10 will now be described.

With initial reference to FIG. 44, of the control wires 230 are attachedto the cuff 102 of the implant 100 so that the implant 100 can becontrolled and positioned after it is removed from the sheath ordelivery catheter 300. The wires 230 are preferably stiff enough toprevent the implant 100 from rotating in a direction that would reducethe effectiveness or prevent the valve 104 from performing its function,of allowing blood flow only in a correct direction. Advantageously, thewires 230 would attach to the implant 100 in a proximal location and ina distal location. This would limit the degrees of freedom of theimplant 100 relative to the wire 230, and minimize the possibility ofthe valve 104 or implant 100 of being damaged by the distal end of thewire 230.

With continued reference to FIG. 44, in the illustrated embodiment, themechanism for coupling the wires 230 to the implant 100 incorporates asheath 470 that extends over most of the length of the wire 230. Thesheath is skived in at least one preferably two, locations to formskive(s) 272. At the skive or skives 472, a portion 474 of the cuff 102or a portion of a member attached to the cuff 102 passes between thewire 230 and the sheath 470. With this method, the wire 230 may bereleased from the cuff 102 by withdrawing the wire 230 from the sheath470 until the tip of the wire 230 extends past the skive or skives 472.In a preferred embodiment, the sheath 470 can be formed from part of thecontrol wire tubes 316 that extend through the deployment catheter 300.

Preferably, three wires 230 are used, but any number between 1 and 10can provide good results. The diameter of the wire 230 can range fromabout 0.002 inches to 0.020 inches. The wires 230 can be manufacturedfrom a metal suitable for blood contact such as nitinol, stainless steelor one of many cobalt chrome nickel and/or iron based alloys. The wires230 can also be made of a polymer that has the desired mechanicalproperties such as a polyimide. The sheath 472 can be manufactured fromthe many polymers suitable for blood contact including nylons Teflon PBXpolyethylene polypropylene polyimides etc. The sheath 470 is preferablysufficiently rigid in the axial direction to prevent the accidentaldisconnection of the valve 100, so the dimensions of the sheath dependon the axial stiffness of the material. A polyimide sheath 470 with a0.026 inches outside diameter and a 0.005 inch thick single wall hasproven adequate, while a grillamid nylon sheath with a 0.030 inchoutside diameter and a 0.007 inch thick single wall has also provenadequate. Preferably the polymer sheath 470 ranges in outside diameterfrom about 0.018 inches to 0.040 inches and in wall thickness from about0.003 inches to about 0.010 inches. Additionally a stainless steel,nitinol or other metallic sheath cab be utilized. In this case, smallerdiameters and thinner wall thicknesses are generally desirable. In oneembodiment, the stainless steel sheath 470 has a 0.014 outer diameterwith an inner diameter of about 0.011 inch and the wire 230 with a 0.009inches outer diameter. With a metallic sheath 470, the preferred wall isabout 0.0005 inch to about 0.0050 inch thick and the preferred outsidediameter is about 0.007 inches to about 0.025 inches. The insidediameter of the sheath 470 should provide clearance to move freely overthe wire 230. A clearance of 0.00 to about 0.007 inches should provideadequately free motion. A lubricant or hydrophilic coating may beapplied to the inside diameter of the sheath 470, or the outsidediameter of the wire 230. Different clearances may be required with lesslubricious polymers. In addition, extrusion parameters may be adjustedto produce a surface finish on the inner diameter of the tube 470 thatoptimizes the motion of the sheath 470 relative to the wire 230. Withsome polymers a rougher surface may result in reduced friction. Asmentioned above, the ideal wall thickness of the sheath 470 depends onthe strength and stiffness of the particular material selected, butlikely ranges between 0.002 and 0.020 inches, single wall thickness.

The proximal end of the deployment control wires 230 preferably containsa lock mechanism (not shown) to prevent the unintended relative motionof the wire relative to the sheath 470. The wires 230 may also beattached to a handle section that allows the relative movement of onewire individually or multiple wires together. In one embodiment thethree wires 230 are attached to a ring, equally spaced around the edgeof the ring. As the ring is moved proximal or distal relative to themain handle component the implant 100 moves proximal or distal relativeto the catheter tip. As the ring is tilted off axis with the axis of thecatheter handle, the implant 100 is tilted in a similar direction.

The deployment control mechanism can performs several functions. Firstas described above, during the initial deployment of the implant 100, itprevents the implant 100 from rotating off axis. Additionally thedeployment control mechanism allows the implant 100 to be repositionsafter it has been removed from the sheath. The wires described abovecould be used to move the implant 100 proximally and distally.

With reference to FIGS. 45A-C, in one embodiment, the implant 100 isinitially deployed partially in the ventricle 32 (FIG. 45A) and thenlater pulled back into position at or near the native valve 34 annulus(FIG. 45B). Preferably, the valve 100 itself is placed just above thenative valve annulus in the aortic root. The implant 100 can then befully deployed (e.g., inflated) such that extends across the nativevalve annulus extending slightly to either side. See FIG. 45C. Thedeployment control wires 230 provide a mechanism for force transmissionbetween the handle of the deployment catheter 300 and the implant 100.By moving all of the deployment control wires 230 together the devicecan be advanced or retracted in a proximal or distal direction. Byadvancing only a portion of the deployment control wires 230 relative tothe other deployment control wires 230, the angle or orientation of thewires can be adjusted relative to the native anatomy. Radiopaque markerson the implant 100 or on the deployment control wires 230 or theradio-opacity of the wires 230 themselves, help to indicate theorientation of the implant 100 as the operator positions and orients theimplant 100.

With reference to FIGS. 46A-C, the deployment control device alsoprovides a method for retracting the implant 100 back into thedeployment catheter 300 if the result is not satisfactory, or if thesizing of the implant could be optimized. Thus, after the implant 100 isfully or partially deployed (FIG. 46A), in addition to providing amechanism to transmit axial force to the implant 100, the wires 230described above provide a guide or ramp to pull the implant 100 backinto the deployment catheter 300 as it is retracted as shown in FIGS.46B and 46C. The implant 100 could be recovered into the deploymentcatheter 300, or a larger recovery sheath (see. e.g., FIG. 50 item 502)could be introduced over the deployment catheter 300 for recovery of theimplant 100.

FIGS. 47A-E illustrate another advantage of the deployment controlsystem. As shown in FIG. 47A, the implant 100 can be partially deployedand the wires used to seat the implant 100 against the native aorticvalve 34. The implant 100 can then be fully deployed as in shown in FIG.47B and then tested as shown in FIG. 47C. If justified by the test, theimplant 100 can be deflated and moved as shown in FIG. 47D to a moreoptimum position. The implant 100 can then be fully deployed andreleased from the control wires as shown in FIG. 48E.

The deployment control systems described herein could be used with thecast in place support structure described in this application, or on aself expanding stent structure, or on a inflatable structure asdescribed by herein. The deployment control device may also be used onother non-vascular devices such as stent grafts for aneurysm exclusionor self-expanding stents for treating stenosis.

FIG. 48 illustrates another embodiment of a deployment control system.In this embodiment, the control wires 230 include a small balloon 480attached to the distal end of the wires 230. The balloons 480 areinserted through a small tube 482 provided on the implant 100. In oneembodiment, the tube 482 is formed of a fabric and can be the samefabric used to form the cuff 102. The deployment control wires 230 arereleased by deflating the balloon 480. The balloon 480 is preferablyabout 0.02 to 0.12 inches diameter and the tube 482 preferably has aslightly smaller inner diameter than the outer diameter of the inflatedballoon 480. The proximal and distal ends of the tube 482 mayadditionally have section(s) of reduced diameter, where the diameter issignificantly smaller than the diameter of the inflated balloon 480.

As described above, the deployment control wires 230 can be used toallow the repositioning of the implant 100 after it has been unsheathed.The deployment control wires 230 are preferably rigid enough to allowthe operator to reposition the implant 100 and to prevent the implant100 from migrating due to the force of blood flow and pressure. Once theimplant 100 is inflated, it is desirable for the wires 230 to beflexible and, in one embodiment, as flexible as the tip of aconventional guidewire. This flexibility allows the implant 100 to takethe same shape and position that it will take after the wires 230 areremoved. This allows both the securement and function of the implant 100to be tested and evaluated before the operator commits to permanentlyimplanting the implant 100. The increased flexibility is preferablyprovided in a plane tangent to the generally cylindrical shape definedby the vessel, where the valve 100 is implanted. Therefore, in apreferred embodiment, the control wires 230 will be particularlyflexible at the tips allowing the device to be nearly free from forcesexerted by the catheter 300, as it would be when disconnected.

Many embodiments of a wire that fulfills the requirements of flexibilityand stiffness are possible. In one embodiment, the wires aremanufactured to have a flexible tip and a less flexible proximalsection. Techniques for manufacturing wires with these properties arewidely known to those skilled in the art of guide wire design andmanufacture. Techniques include grinding a tapered control wire as shownin FIG. 49A and or stepped shoulders to the diameter of the wires. Inanother embodiment, the wire is wrapped with coils of similar type ordifferent materials to provide a soft feel to the distal section.

In another embodiment, which is illustrated in FIG. 49B, the deploymentcontrol wire 230 comprises of an inner wire 482 and an outer tube 484over the inner wire 482. When a stiff system is desired, the inner wire482 and tube 484 are used together. When a more flexible control wire230 is desired, either the inner wire 482 or the tube 484 is used alone.In one embodiment, the inner wire 482 is preferably manufactured from ametal such as nitinol or stainless steel and the tube 484 can bemetallic or polymeric. The tube 484 may be cut in a spiral pattern orhave segments cut out of it or a skive cut in it to create the desiredflexibility in the required areas. In another embodiment, patterns canbe cut in the tube 484 as seen in U.S. Patent Publication 2002/0151961A1 to Lashinski et al., which is hereby incorporated by referenceherein. In this embodiment, there are patterns cut in the tube 484 toprovide defined shape as the tube is deflected. In other embodiments,guidewires utilizing slots cut into a tube as seen by neurovascularproducts from Boston Scientific/Target Therapeutics can be used.

With reference to FIG. 49C and FIG. 49D, in another embodiment,deployment control wires with variable stiffness are created byutilizing a wire 486 and a sheath 488 as a system where each has apreferred bending plane. When the wire 486 and the sheath 488 arerotated so that their preferred bending planes align (see FIG. 49D) theyhave good flexibility in the plane where flexibility is required. When astiffer system is desired, the wire 486 and sheath 484 are rotated sothat their preferred bending planes are out of alignment (see FIG. 49C),preferably approximately 90 degrees out of alignment. In thisconfiguration a less flexible system is produced. The wires 486 andsheath 495 cross sectional profile may be round with single or multipleflats to create a “D” shaped cross section, for example, as shown in theillustrated embodiment of FIGS. 49C and 49D. The

Recovery Tools and Techniques

Current valve systems are often deployed through a stent-based mechanismwhere the valve is sewn to the support structure. In the inflatedembodiments described herein, the structure is added to the implantsecondarily via the inflation fluid. This allows the user to inflate orpressurize the implant with any number of media including one that willsolidify. As such, if the operator desires, the implant 100 can be movedbefore the inflation media is solidified or depressurization can allowfor movement of the implant within the body. Since catheter baseddevices tend to be small in diameter to reduce trauma to the vessel andallow for easier access to entry, it often difficult to remove devicessuch as stents once they have been exposed or introduced into thevasculature. However, as will be explained below, a device describedherein enables a percutaneous aortic valve to be recovered from the bodyand reintroduced retrograde to the introducer.

FIG. 50 illustrates one embodiment of a device 500 for recapturing animplant 100. As shown, the device 500 comprises an outer tubular sheath502. A tubular recovery sheath 504 is inserted through the outer sheath502. The recovery sheath 504 includes a sox or braided structure 506,which is coupled to the distal end of the sheath 504 and is configuredto capture the implant into the device 500 without harm to the patient.Relative movement of the recovery sheath 504 with respect to the outersheath 502 would expose the braid 506 when introduced into the body. Bypulling a implant 100 into the braided section it may be safelyreintroduced into a introducer or sheath. The braid 506 allows theimplant to be guided into an introducer without harm or worry of theimplant being tethered or compiled to a larger diameter where it may notfit into the inner diameter of a sheath.

A hemostasis valve (not shown) is preferably attached to the proximalend of the device 500. Also at the proximal end, a flush port andstop-cock can be provided for fluid introduction. In one embodiment, theinner shaft 504 would have a length of about 40 to 60 centimeters and adiameter of about 2 to 18 millimeters. In a modified embodiment, thedistal end 508 of the braid section 506 could be attached to end of theouter coaxial sheath 502. This would allow relative motion between thetwo sheaths 502, 504 and allow the braided section 506 to be invertedupon it self. The braided section 506 can be formed or shaped into afunnel as shown in FIG. 50 so that it is in contact with the aortic wallwhen introduced into the body. The braid 506 may be constructed withmaterials such as polymeric strands or Nitinol, stainless steel or MP35Nwire and attached by glue or thermal bonding techniques know in theindustry. This wire, strand or ribbon may have a diameter or dimensionof about 0.002 to 0.020 of an inch. The set or expanded shape would beabout 1.00 to 1.50 inches and the length of the braid 506 would measureabout 6 to 9 inches in length. It is also possible to have the innersheath 504 and outer sheath 504 connected leaving the braid 506 fixed inlength and diameter. The relative motion between the two sheaths 502,504 would be limited or eliminated depending upon the construction ofthe device 500. Both configurations may require a capture sheath tocollapse the braided section 506 while it is being inserted into theintroducer. The diameter of this sheath would be about 24 F or similarin diameter to the introducer. Once inserted through the sheath, thedevice 500 is expelled out the introducer and exposed to the descendingaorta. Hemostasis valves will prevent blood from leaking proximally outthe catheter shaft.

In another embodiment the slit tubing is replaced by a fabric cone,where the fabric cone may contain a feature such as a preshaped wire ora balloon to facilitate its opening.

The braided cone 506 can be formed by heat setting or other manners intoa cone shape with a free diameter slightly larger than the patientsaorta. In another embodiment, the braided cone is manufactured fromloops of wire so that the cut ends of the wire are all located at theproximal end of the cone. The wires used to manufacture the conepreferably have a diameter from 0.002 in to 0.020 in. The wires may alsobe replaced by ribbons having a thickness between 0.002 in and 0.020 inand a width between 0.003 in and 0.030 in. The diameter of the small endof the cone is preferably between 0.007 in and 0.3 in the cone ispreferably be capable of collapsing to a diameter small enough to passthrough the desired introducer size. The large end of the cone sectionpreferably expands to a diameter similar to or slightly larger than thetypical human aorta, or 0.75 in to 1.50 in.

In one embodiment, the separate recovery device 500 is supplied tofacilitate the recapture of the implant in the event that the prostheticvalve did not produce the desired result in the patient. To recapture aninflatable aortic implant 100 as describe herein, the delivery catheter300 for the device would be removed leaving inflation tubes 318 and ordeployment control tubes 316 tethered to the implant 100. By insertingthe retrieval catheter 500 over these connections the implant 100 is nowcoaxial to the retrieval system 500 and ready to be removed from thebody. By advancing the retrieval catheter 500 over the implant 100 or bypulling the control lines 230, the implant 100 can be retracted into thebraided section 506. The implant 100 is now covered and may safely bepulled into the sheath 502 and removed from the body.

FIG. 51 illustrated another embodiment of a retrieval device/system.500. In this embodiment, the distal end of the inner sheath 502 includesa spilt section 510 that is flared to funnel the implant into the device500. In one embodiment, the distal end of the inner sheath 504 would beslit longitudinally about 1 to 2 inches in length and radially is 4 to12 times. This would leave a series of narrow bands or strips 512 to bepreshaped open or rolled back. In the illustrated embodiments, thestrips 512 are curved outward away from the center line of the tube.This would require the retrieval outer sheath 502 to be advanced overthe flairs 512 to capture the implant 100 to be removed. The implant 100can include control wires 230 spaced radially to gather the device intoin a similar manner as described above. The wires may be stainlesssteel, Nitinol or other suitable materials generally accepted in medicaldevices. Formation of this wires would allow them to be radiallyexpandable to contact the aortic wall allowing the device to be pulledinto the sheath.

Other applications for these recapturing systems may be advantageous fordevices such as stents (coronary and peripheral), PFO and ASD closuredevices, micro coils and other implantable devices that may needretrieval from the body. Currently snares and other tools are used todrag devices out of the body however, many devices will be hung up oncatheters or introducers as they are removed. By creating a basket toprotect the device from these events, removal becomes simpler and safer.

Another method for device recovery includes providing a string woventhrough the prosthetic valve 100. As tension is applied to the stringthe prosthetic valve 100 collapses back down, to a size small enough tobe recovered into the delivery sheath, the introducer or a recoverysheath.

Excision and Debulking Devices

The procedure of implanting a valve preferably begins with enlarging thevalve annulus. This could be performed with a simple balloonvalvuloplasty. However, in many instances this is not sufficiently.Thus, before a prosthetic valve is replaced in a surgical procedure, thesurgeon often modifies or removes the native valve leaflets, andespecially any calcification or vegetations in the area As will beexplained in more detail below, in order to preserve outflow from theheart, between the time that the native aortic valve is excised ordebulked and the time that a prosthetic valve is implanted, a temporaryvalve 520 (see FIG. 52A) can be installed. The temporary valve 520 canbe placed in the aorta 36 in the arch or in the descending or ascendingaorta. Examples of these types of valves are described in U.S. Pat. No.3,671,979 and U.S. Pat. No. 4,056,854, which are hereby incorporated byreference herein. Many other temporary valve designs are possible;however, flexible polymer or tissue valves are the preferred valve typebecause they can be easily delivered via catheter. Several versions offlexible polymer valves are possible, for example, a “duck bill”,tricuspid or bicuspid style valve can be used. Alternatively. anumbrella style valve or a windsock type valve could be used. Thetemporary valve 520 can be sealing and temporarily engaged to the wallof the aorta 36 by several methods including a self-expanding stent oran inflatable balloon like structure at the base of the valve.Additionally, the temporary 520 may be entirely inflatable or utilizecombinations of polymers such as nylon, Teflon, Dacron or polypropylenewith metallic elements including Nitinol, stainless steel, or othergenerally acceptable materials use in medical devices. There may beradiopaque markers attached to the temporary valve for proper placementand anchors deployable from the temporary valve or passively attachedmay aid the device in securment.

In one embodiment, the temporary valve 520 can be configured in a mannersimilar to the implant 100 described above. In such an embodiment, thetemporary valve 520 would be delivered via catheterization technique bydelivering a collapsed temporary valve and filling the valve body orcuff with fluid to provide structure or by compressing a valve assemblyinto a catheter for delivery and introducing the valve by removing asheath to introduce the device to the targeted implantation site. It isalso possible to unroll or unwrap a valve assembly from a catheter fordelivery. Any method of delivery will suffice as long as the device canbe safely removed once the removal and introduction of the new valve hasbeen completed.

The temporary valve 520 should provide a manner for a catheter to passacross the temporary valve while still maintaining flow. The temporaryvalve 520 can be delivered with a guidewire advanced through the valveto allow guide wire compatible devices to be easily advanced across thevalve. If an umbrella type valve is used blood flows between the deviceand the wall of the aorta. In this case the guidewire or catheter maypass around the valve rather than through the valve.

A modified method to using a temporary valve is to use a percutaneousbypass procedure. When this procedure is performed it is no longernecessary to maintain the flow through the aortic outflow tract. Theaorta may be occluded during the excision step and the debris and fluidfrom the excised area may be aspirated after or during the excisionstep. In a percutaneous bypass procedure blood is oxygenatedextracorporally and reintroduced into the body. A cardiopelegia solutionis used to stop the heart-beat.

With reference to FIG. 52B, an embolic protection device 522 isdesirable, or necessary because as the calcified or diseased valve isremoved or dissected embolic debris may likely be released. It may bedesirable to locate the embolic protection device 522 downstream fromthe temporary valve 520 so that it will capture any embolized thrombosisand debris from the valve 34. It also may be desirable to locate theembolic protection device 522 below the ostia 521 of the coronaryarteries. If this location is selected it may be difficult or impossibleto locate the filter 522 downstream from the temporary valve 520.Filtration size can range from about 25 microns to 500 microns in size.The filter 524 of the protection device 522 may be made from Nitinol,MP35N, stainless steel or any acceptable polymeric material used inmedical devices.

Many various tools are capable of removing portions of the aortic valve34 or for removing calcification from the aortic valve 34. Examples ofsuch tools that are known for surgical applications or for percutaneousapplications include ultrasonic energy sources such as CUSA, hand toolssuch as cutters or knives and fluids that may dissolve or soften thetissue and or calcium to be removed. As shown in FIG. 52B, in oneembodiment, the excise tool 530 is positioned generally within thefilter 524.

In one embodiment, an ultrasound transducer may be positioned near acatheter tip and used as a tool to break up calcium and cause it torelease from the valve tissue. This method was used for the surgicalrepair of calcified aortic valves. Unfortunately, the procedure can alsodamaged the healthy portions of the leaflets causing aorticinsufficiency chronically. Typically, the aortic insufficiency woulddevelop in one to two years. In some patients, the native valve wasdestroyed during the procedure. As a preparation for valve removal, apercutaneous adaptation of this technique may be appropriate. Inaddition to the ultrasound catheter, some method of collection thecalcified tissue is often required. One method is the embolic protectionfilter described in this application. Alternatively, suction could beapplied to the catheter tip, to remove the small particles. With eithermethod, large nodules of calcium may be released from the native tissue.If the nodules are larger than the catheter they must be broken upbefore they can be safely removed percutaneously. Preferably, theultrasound transducer can be manipulated to break up these large nodulesinto particles small enough that they can be removed. This technology isdescribed in U.S. Pat. Nos. 4,827,911, 4,931,04, 5,015,227, 4,750,488,4,750,901 and 4,922,902, which are hereby incorporated by referenceherein. The frequency range for these devices is often about 10-50 KHzbut seems to be optimal at about 35 Khz.

Another tool that can be used to excise the native valve 34 may comprisemultiple external energy sources that are focused on the tissue to beremoved from different directions. This technique can be used withseveral energy sources, for example ultrasound energy may be used inthis way. Radiation energy may also be used in this way, by a methodreferred to as a gamma knife.

A heated wire system can also be used to cut the aortic valve out fromthe annulus. In such an embodiment, the wire may be mounted on acatheter and heated by means such as electric resistance or RF energy.The wire may be manipulated in the area of the valve to be removed, andlocated by balloons or wires. Wire sizes may range from 0.005-0.100inches in diameter and are typically made from a Ni-chrome material.

In another embodiment, a laser can be used to cut the calcified tissueapart. The laser energy could be transmitted fiber optically through acatheter and applied to the calcified tissue at the catheter tip. Thecatheter tip may be manipulated by the operator to direct energy to thesite-specific area causing ablation or cutting the tissue and ordiseased material. It is important that the laser wavelength is correctand will couple to the material to be affected. There may be a need toadjust the wavelength, rep rate and energy density to customize theremoval process.

In yet another embodiment, the calcified valve tissue may be broken upand removed using a cutting balloon, or an inflatable balloon with metalor rigid plastic blades along its length. An example of this is U.S.Pat. No. 5,616,149, which is hereby incorporated by reference herein. Asthe balloon is expanded the blades are forced into the tissue causing itto break apart. Mulitple inflations may be required to create asufficiently large valve area. In one embodiment the balloon is mountedon a torquable catheter allowing a partially inflated balloon to betorqued scraping tissue away from the valve annulus. This balloon sourcemay be used in the “hot-wire” application above to cut the tissue in apie shaped pattern before removal or exclusion.

Several of the tools described for removing portions of the aortic valvemay remove portions of valve or calcium that are larger than can passthrough a catheter. In these cases a catheter with a provision topulverize and extract the excised material may be needed. In oneembodiment the catheter includes a rotating auger near its tip to breakup the large particles and feed them back through the catheter shaft.Suction may also be applied to the catheter to prevent smaller particlesfrom exiting the catheter tip. Examples of this may include theRotoBlader device produced by Boston Scientific but may be housed in acatheter to limit the escape of particles down stream.

FIGS. 53A-54C illustrate one embodiment of an excise device 530 whichcomprises a punch and die that can be used to punch out sections oftissue. The device 530 comprises a punch or cutter 532 with a sharp edge534 that is moveably positioned within a channel or cavity 535 of acatheter body 540 to collect the removed sections of tissue. As will beexplained below, the punch 532 can be actuated by pushing or pulling awire 539 through the length of the catheter, by a hydraulic actuation,or by a screw device near the catheter tip that translates a rotationalforce transmitted through a flexible shaft into an axial or linear forcethat actuates the punch 532.

With continued reference to FIGS. 53A-54C, the cutting action ispreferably from distal to proximal to move the material into acatheter's inner diameter. Although not shown, the device 530 can use aspring force to eject the material and a trap or door to retain thematerial once in the catheter shaft. As shown, a cutting edge 542 isformed in by a window 544 formed in the catheter body 540. The widow 544forms a cutting edge that is generally perpendicular to the diameter ofthe catheter 540 or, in a modified embodiment, at an angle to provide alower cutting force. The cutting edge 542 and or the puncher 532 canhave any of a variety of shapes such as hyperboloid, triangular, diamondor serrated that would aid in cutting the material to be removed. Thecutting edge 542 and/or punch 532 can also use a vibrating or ultrasonicenergy to lower the forces required to cut the material. These can bedelivered through the catheter 540 and may include transducers, motorsor RF energy. In one modified embodiment, the punch 532 is replaced witha rotating blade. The entire device 530 is preferably flexible andconfigured to use normal catheterization tools including contrast,introducers, saline, guidewires etc/.

In the preferred embodiment, the cutting action is performed by pullingthe punch 532 proximally into the cutting edge 542. The punch 532 iscoupled to the wire 539, which extends through the catheter and isactuated by a handle 546 provided at the proximal end of the device 530.By cutting in this direction the excised tissue is pulled into thecatheter 540, and the wire 539 which transmits the force is loaded intension. An aspiration function is also incorporated into the lumen 535into which the excised tissue is pulled. By maintaining a minimal fluidflow out through the catheter lumen 535 the risk of embolic events mayalso be minimized. A spring (not shown) can be provided at the distalend 552 of the device to pull the punch 532 distally after the wire 539is released.

For a device such that described above or a DCA device, it isadvantageous for the cutting portion of the device to be movable toengage the tissue. A balloon or forced wires which forces the cuttingportion against tissue, is traditionally used with a DCA device, howeverthis prevents perfusion. In the illustrated embodiment of FIGS. 54A-54C,a strap or straps 550 extend the length of the catheter 540 and aid thedevice 530 in engagement. The straps 550 are attached near the cathetertip 552 to the catheter 540 and on the opposing side of the cutting edge542. A section 551 of the strap or straps 540 is free in the area nearthe cutting portion of the device 530. As the straps 550 are advancedrelative to the catheter shaft 540, they are forced to bow out away fromthe cutting portion of the device 530. This forces the cutting portionof the device 530 into the tissue. The operator may rotate the device530 to engage the desired tissue.

In a modified embodiment, the straps 550 extend axially across theportion of the catheter where the cutting takes place, and attach to anelongate member which is free to move axially relative to the elongatemember that is attached to the cutting mechanism. The two elongatemembers are preferably located coaxially. In one embodiment bothelongate members are polymer tubes.

FIGS. 55A and 55B illustrate another embodiment of the excise device.This embodiment is similar to the embodiment described above withreference to FIGS. 53A-54C in that it includes a catheter body 540, acutting edge 542 and a tissue punch 532. In this embodiment, the tissuepunch 532 is coupled to a return spring 554 and is actuated bypressurized fluid that is supplied through an inflation lumen 556 to achamber 558 at the distal end 552 of the catheter body 540. A seal 560is provided between the punch 532 and the catheter body 540 to seal thechamber 558. By increasing the pressure in the pressurized chamber 558,the punch 532 is moved proximally against the cutting edge 542. When thepressure is decreased, the punch 532 is moved distally by the spring554. Barbs 560 can be provided in the catheter body 540 to retain tissueintroduced through the window 544. The inflation lumen 556 can beattached to the catheter body 540 by an adhesive 564 as shown in FIG.55B.

FIGS. 56A-C illustrate another modified embodiment of an excise device530. In this embodiment, cutting wires 570 extend through lumens 572provided in a catheter body 574. The cutting wires 570 can be mounted attheir distal end to the distal portion of the catheter body 574. Most ofthe length of the cutting wires is encapsulated in the lumens 572 of thecatheter body 574. A skive 576 is provided at the distal portion toexpose a short portion 578 of the wires 570 just proximal to the pointwhere the wires 570 are attached to the catheter body 574. In oneembodiment, the skive 576 is between about 5 and 100 mm in lengthpreferably between about 10 and 30 mm in length. As the proximal ends ofthe wires 570 are advanced relative to the catheter body 574 the distalportions 578 bow out away from the catheter body 574 through the skive576. The wires 570 may have a cross section that provides a preferentialbending plane and prevents their rotation within the lumen 572 of thecatheter body 574. This may help the wires 570 deploy in a controlledorientation. The exposed portions 578 of the wire 570 can includecutting surfaces that are exposed to the tissue when the wires 570 areadvanced. In another embodiment, this device 530 can be configured suchthat the wires 570 can be deployed, heated and then advanced orretracted through the valve annulus or it may be heated and thenactuated within the valve annulus. The catheter body 574 can alsoinclude stiffening wires 580 positioned in lumens 582 as shown in FIG.56B.

FIG. 56D illustrates another modified embodiment of an excise device530. In this embodiment, the device comprises an outer protective sheath900, an inner sheath 902 that can track over a guidewire 904 and anintermediate member 906 positioned between the outer and inner sheaths900, 902. The intermediate member 906 includes an cutting structure 908,which can expand as the outer sheath 900 is withdrawn to expose thecutting structure 908. In this embodiment, the cutting structure 906comprises a plurality of elongated cutting members 910, which aresupported by annular spring members 912. The device can be positionedwithin the valve and then the outer sheath 900 is withdrawn to exposethe cutting members 910. The device can be rotated to provide a cuttingaction.

In yet another embodiment, an atherectomy catheter device (not shown)includes a housing at the distal end of a substantially round housingtorque cable. A cutter torque cable is disposed within the housing andincludes a rotatable and translatable cutter at its distal end. Thehousing includes a window into which an atheroma protrudes. The cuttersevers the atheroma. A nose cone attached to the distal end of thehousing collects and stores severed atheroma. A stabilizing member isattached to the exterior of the housing opposite the window. Astabilizing member can be provided and includes a balloon having aninflation lumen disposed within the housing. In a modified embodiment, amechanical stabilizing member provided and includes a distal endattached to the distal end of the housing or to the nose cone, and aproximal end coupled to a stabilizing cable disposed within a cablelumen of the housing torque cable. The stabilizing cable can be advanceddistally to bow the stabilizing member away from the housing andwithdrawn proximally to flatten the stabilizing member against thehousing, alternately urging the window side of the housing onto theatheroma and allowing it to retreat therefrom.

Another method for removing calcification and vegetation from the valvearea is with a pharmacological agent. For example, an agent thatdissolves calcium is secreted by osteoblasts. An agent similar to thiscould be utilized prior to the valve replacement procedure.Alternatively an agent like this could be coated on the valve leafletsor on another portion of the prosthesis so that it slowly elutes overthe life of the valve. This would prevent or minimize the calcificationthat contributes to the deterioration of the valve. The agent could becontained in a polymer coating, in a porous metallic coating, or in thetissue itself

To aid removal or debulking, the calcified tissue may be visualized byechocardiography and or fluoroscopy, ECHO, MRI, CT scan as is known inthe art.

With reference back to FIG. 52B, an access sheath attached to theprotection filter device 522 allows the excise device 530 or other toolsto access the work area between the left ventricle 32 and the filter530. The access catheter may be made of a flexible material which can befolded inside a delivery catheter. This allows the delivery catheter tobe a low profile device while relatively large profile devices may beintroduced through the access catheter. In one embodiment, a deliverycatheter containing the temporary valve and embolic protection deviceand access catheter is advanced through the vasculature. The devices aredeployed and the delivery catheter is removed completely from thepatient. The access catheter then expands to an inside diameter largeenough for the required devices for valve removal and replacement topass through.

Many of the devices described above for removing or cutting the valvecommissures could benefit from the use of a centering balloon to locatethe catheter in the center of the native annulus while the cuttingoccurs. The centering balloon could be located proximal or distal to thevalve, or balloons could be located both proximal and distal. Theballoons could optionally contain perfusion lumens.

In a modified embodiment, the method of enlarging the annulus involves aprocess of shrinking tissue instead of or in addition to removingtissue. For example, it is possible to shrink collagen type tissue bythe application of heat. In such an embodiment, the tissue is preferablyheated to a temperature of 50 to 65 C. More preferably the tissue isheated to 55 to 60 C in one embodiment the tissue is heated to atemperature of 59 C. The heating may be accomplished from a variety ofenergy sources, one particularly advantageous energy source for apercutaneous application is RF energy. Accordingly, a catheter with aheated element on the tip may be used to heat specific portions of thevalve.

In one embodiment, the catheter incorporates a needle near the heatedportion. The portion of the catheter intended to transfer heat to theleaflet tissue is positioned below the surface of the leaflet. Thisminimizes the transmission of heat into the bloodstream, whilemaximizing the transmission of heat to the leaflet tissue.

In another embodiment the heating step is applied by a tool that alsodilates the annulus. This tool may be a balloon inflated with a heatedsolution or a dilation device that contains heating elements, such asthose described in this application using deflected straps.

In general, the application of heat is intended to affect the portionsof the leaflets nearest to the center of the valve. Excessive shrinkingof the outer portion of the valve annulus may cause the effectiveorifice area to be reduced. Shrinking an area near the tip or free edgeof each leaflet will cause the effective orifice area to be increased.It may additionally release the calcium deposits within the valve tissuethus providing a large effective orifice area to implant a new valve.

Procedures for Deploying the Implant

Various procedures and methods for deploying an implant 100 in theaortic position will now be described. In one embodiment, the methodgenerally comprises gaining access to the aorta, most often through thefemoral artery. A balloon valvuloplasty may optionally be performed inthe case of aortic stenosis, or another method may be used to remove ordebulk the native valve as described above. A delivery sheath orcatheter is advanced over the aortic arch and past the aortic valve. Theouter sheath of the catheter is retracted exposing the valve and cuff.Fluid is used to inflate the valve and a second inflation fluid may beused to partially form the implant. This allows the distal portion ofthe implant to open to its full diameter. The proximal portion of theimplant may be slightly restricted by the deployment control mechanism.In general, the amount that the deployment-control mechanism restrictsthe diameter of the proximal end of the device depends on the length ofthe wires extend past the outer sheath, which an be adjusted by theoperator. Alternatively, in some embodiments, the implant containsmultiple inflation ports to allow the operator to inflate specific areasof the implant different amounts. In another embodiment, burst discs orflow restricters are used to control the inflation of the proximalportion of the implant 100. The implant is then pulled back intoposition. The distal ring seats on the ventricular side of the aorticannulus. A balloon may be used to dilate or redilate the device ifnecessary. At this time, the deployment control wires may act to helpseparate fused commissures by the same mechanism a cutting balloon cancrack fibrous or calcified lesions. Additional casting material may beadded to inflate the implant fully. The inflation lumen is thendisconnected, and the deployment control wire(s) are then disconnected,and the catheter is withdrawn leaving the device behind. In modifiedembodiments, these steps may be reversed or their order modified ifdesired.

The above-describe method generally describes an embodiment for thereplacement of the aortic valve. However, similar methods could be usedto replace the pulmonary valve or the mitral or tricuspid valves. Forexample, the pulmonary valve could be accessed through the venoussystem, either through the femoral vein or the jugular vein. The mitralvalve could be accessed through the venous system as described above andthen trans-septaly accessing the left atrium from the right atrium.Alternatively, the mitral valve could be accessed through the arterialsystem as described for the aortic valve, additionally the catheter canbe used to pass through the aortic valve and then back up to the mitralvalve.

For mitral valve replacement, the implant may require a shorter bodylength (e.g., 1-4 cm) and would mount in the native mitral valve area.It may be delivered from the right side of the heart from the femoralvein up through the inferior vena cava and into the right atrium. Fromthere, a transeptal-puncture may be made for entry into the left atriumand access to the mitral valve. Once in the left atrium, the implantwould be delivered with the valve pointing down to allow flow from theleft atrium to the left ventrical. A similar shape would allow thedevice to be deployed in the left atrium and advanced into the leftventrical. The proximal ring may require inflation to hold the device inthe left ventrical by creating a diameter difference between the mitralorifice and the proximal cuff diameter. Here as with the aorticreplacement, the mitral valve may require partial removal or cutting ofthe valve or chorde to allow the native valve to be excluded and provideroom for the replacement valve to be implanted. This may be achieved byballoon valvuloplasty, cutting techniques such as a cutting balloon orby utilizing a hot-wire or knife to cut slits in the native valve toallow for exclusion. Once the native valve has been prepared for the newvalve, the mitral valve orifice may be crossed with the distal portionof the implant and the distal portion may be inflated for proper shapeand structure. At this time, the native valve will have been excludedand the replacement valve will be fully operational.

Other methods of mitral replacement would include a transapical deliverywhere the patent would receive a small puncture in the chest cavitywhere the operator could access the apex of the heart similar to aventricular assist device implantation. Once access is gained to theleft ventrical, the aortic and mitral valves are a direct pathway forimplantation of the replacement valve. In this case, the aortic valvewould be delivered with the flow path in the same direction as thecatheter. For the mitral valve, the flow path would be against thedirection of implantation. Both may still utilize the base of theimplant to anchor the device using diameter differences to secure thedevice. It may be desirable to also use a hook or barb that couldprotrude from the cuff either passively or actively as the cuff isfilled with fluid. The barb could be singular or a plurality of barbs orhooks could be used where the length could be between 1-5 millimeters inlength depending upon the tissue composition. Where a longer barb may berequired if the tissue is soft or flexible. It may be desired to haveshorter lengths if the tissue is a stiffer more fibrous structure wherethe barbs could hold better.

For the pulmonary and tricuspid valve placement, the operator couldaccess the femoral vein or internal jugular (IJ) vein for insertion ofthe delivery system. As with the transeptal mitral valve approach thedelivery system and device would be introduced either superiorly orinferiorly to the vena cava and to the right atrium and right ventricalwhere the pulmonary and tricuspid valves are accessible. The femoralapproach is preferable due to the acute bends the delivery system wouldbe required to make from a superior or IJ access. Once in the rightventrical the device could be delivered similarly to the aortic methodwhere the cuff utilizes the base of the pulmonary valve for a positiveanchor with a diameter difference holding it from migrating distally. Itmay be desirable to also use a hook or barb that could protrude from thecuff either passively or actively as the cuff is filled with fluid. Thebarb could be singular or a plurality of barbs or hooks could be usedwhere the length could be between 1-5 millimeters in length dependingupon the tissue composition. Where a longer barb may be required if thetissue is soft or flexible. It may be desired to have shorter lengths ifthe tissue is a stiffer more fibrous structure where the barbs couldhold better.

In any placement, the proper valve configuration would be chosen by theperformance of each required application. For instance the aortic valvemay require a two or three-leaflet valve that will require a high degreeof resistance to stress and fatigue due to the high velocities andmovement. The pulmonary valve may require a lesser valve due to the morepassive nature or the lower pressure that the valve is required tosupport. Lengths may vary and will be dependant upon the valve andstructure surrounding them. A shorter valve (1-4 centimeters) may berequired for the mitral but the aortic may allow for a longer valve (1-8centimeter) where there is more room to work. In any application, themaximum orifice size is generally desired since the cross sectional areahelps determine the outflow volume. The aortic cross sectional area mayvary from nearly 0.00 square centimeters in a heavily calcified valve toabout 5 square centimeters in a healthy valve. Most cases the desire inreplacement is to increase a cross sectional area for additional flow.

During the procedure or during patient selection, or follow-up, variousimaging techniques can be used. These include fluoroscopy, chest x-ray,CT scan and MRI. In addition, during the procedure or during patientselection, or follow-up, various flows and pressures may be monitored,for example echocardiography may be used to monitor the flow of bloodthrough the relevant chambers and conduits of the heart. Pulmonary wedgepressure, left atrial pressure and left ventricular pressures may all berecorded and monitored. It may be desirable to use a measurement tool todetermine the size of valve required or to determine if the anatomyprovides enough room to allow implantation of a valve. In the past,marker-wires have been used to measure linear distance and a similartechnique could be used in this application to measure a distance suchas the distance from a coronary artery to the annulus of the aorticvalve. To measure the diameter of a valve, a balloon with a controlledcompliance could be used. Ideally, the balloon would be very compliantand inflated with volume control, but a semi compliant balloon couldalso be used and inflated with a normal interventional cardiologyinflation device. The compliance curve of the balloon could then be usedto relate the pressure to the diameter. The diameter range of valves inthe heart may range from 10-50 mm in diameter and 2-40 mm in length. Asimilar sizing balloon has been used for sizing septal defects.

In one embodiment, implantation of a prosthetic valve includes the stepof dilating the valve after it is positioned and functioning within thenative anatomy. If the dilation step is used to replace a balloonvalvuloplasty prior to the inflation of the balloon the cuff willminimize the embolization from the dilation. The dilation of thefunctional implant step may also be used in patients where avalvuloplasty is performed prior to implantation of the device, butwhere the outflow area is not as large as desired. Certain embodimentsof the implantable prosthetic valve include deployment control wires orstiffening wires. If these features are present in the implant at thetime of post dilation, then the features may act to concentrate theforce from the deployment of the balloon in a mechanism similar to thefunction of a cutting balloon commonly known in interventionalcardiology.

To gain access to the aortic valve the femoral arteries (radial,brachial, carotid) can be used to introduce tools into the vascularsystem. Once in the arterial conduits, catheters may be advanced to theaortic arch and the native aortic valve. As discussed above, it may benecessary to install a temporary valve to allow gating of the blood flowwhile the work is being completed on the native valve. This will providetime for the interventional cardiologist to prepare for removal andinstallation of a new aortic valve. The placement of the temporary valvecould be between the native valve and the coronary arteries, or thevalve could be placed in a location between the coronary arteries andthe location where the great vessels branch off from the aorta or at anyother location within the patients aorta. Placing a valve in these nonnative locations to treat aortic insufficiency has been proven effectivein clinical experience by the use of the Huffnagel valve. Placing atemporary valve in these locations has been described by Moulolupos andBoretos. A guidewire or pig-tail catheter may be used to pass a stiffercatheter through the stenotic hole in the aortic valve. It may benecessary to install a filtration device to protect any vesselsincluding the coronary tree from debris as the valve is loosened andremoved. This filter may be placed in the region of the aortic valvejust before the coronary ostia or distal to the sinus and just beforethe great vessels. Once through the valve opening a balloon may bepassed into the aortic valve to predilate the region and loosen anycalcium. This may aid in the removal of the tissue that may be calcifiedand or fibrosed. The use of a catheter to deliver energy such asultrasonic, RF, heat or laser may additionally break or loosen thetissue including the calcification in and on the leaflets. There arechemical treatments that have shown some promise in dissolving thecalcium such as Corazon Inc. of California (see U.S. Pat. No.6,755,811). The ultrasonic energy device is described in detail throughU.S. Pat. No. 4,827,911 and has a proven track record known as CUSA toremove calcium in a surgical suite from valve tissue. This has shownpromise acutely but will denature the collagen tissue and result in adegeneration of the valve tissue remaining in about a year leaving apoorly functioning valve. After a filter has been installed and thevalve tissue has been softened, a template may be used to define thearea to be removed. This template will define the hole and prevent theremoval of healthy tissue. At this time the valve is ready to be removedwith adequate time since the temporary valve will be functioning whenthe native valve is removed. This will be important to not allow thepatient to go from aortic stenosis to aortic insuffiency. The removaltool may now be passed through the stenotic valve and begin the removalprocess of the native valve. As mentioned above and in patents and USapplications such as 20040116951 Rosengart there are many ways to removetissue from this region.

The embodiments described above provide a technique that lends itselfwell to delivering a catheter based valve removal tool. Through apushing and pulling force the pin and die set as seen in the drawingswill allow the valve to be removed in a controlled manner while leavingthe material in a catheter shaft for removal. It is asserted that thisis the first that allows the aortic outflow track to be gated or valvetemporarily. Though an aortic balloon pump may function as a temporaryor supplementary valve in some conditions, the balloon pump isineffective and dangerous in patients with aortic insufficiency. Aremoved or partially removed aortic valve constitutes severe aorticstenosis.

FIGS. 57A-57O will now be used to describe a embodiment of procedure forinstalling an prosthetic aortic valve 100, which utilizes some of theprocedures described above. In particular, the illustrate embodimentincludes the steps of placing a temporary valve, optionally placing anembolic protection device, removing or debulking or destroying all orpart of the stenotic valve, implanting a permanent prosthetic valve, andthen removing the temporary valve and embolic protection device. Ofcourse those of skill in the art will recognize that not all of thesesteps are required and/or that the order of certain steps can bechanges. In addition, those of skill in the art will recognize variousmodified embodiments of the steps described herein.

As shown in FIG. 57A, access to the aorta can be provided by an accesssheath 600 through the femoral artery 602. A deployment catheter 604 isadvanced over guidewires 606 through the access sheath and through thefemoral artery toward the aortic arch 10 (FIG. 57B) The deploymentcatheter 620 is used to implant a temporary valve 520, as describedabove with reference to FIG. 52A. The temporary valve 520 is implantedpreferably as a first step, although an embolic protection filter mayalso be implanted as a first step. For the treatment of a stenosedaortic valve 34, the temporary valve 520 is placed in the aorta 36. Thevalve 520 may be placed in the ascending or descending aorta. A valve520 in this position has been proven moderately effective by experiencewith the Hufnagel valve, and was described in similar designs disclosedby Moulolupos U.S. Pat. No. 3,671,979 and Boretos U.S. Pat. No.4,056,854. Although a valve placed beyond the coronary arteries does notprovide ideal performance as a long term implant, the function of thevalve in this location has been proven sufficient for short-term use. Ina healthy patient, the coronary arteries fill during diastole, howeverin a patient with severe aortic insufficiency the pressure required tofill the coronaries in diastole is not present. These patients are ableto perfuse the coronary arteries sufficiently for survival.

Alternatively, the temporary valve 520 may be placed so that it actsbetween the native aortic valve and the coronary arteries although itsphysical position would likely extend well above the coronary arteries.In this embodiment the inlet side of the temporary valve would seal tothe aortic wall just below the coronary arteries. The outlet side of thevalve would extend up beyond the coronary arteries. The mid portion ofthe valve and the outlet side of the valve would have an outsidediameter smaller than the inside diameter of the patients aorta. Thiswould allow blood flow from the outlet of the valve, around the outsideof the valve back towards the ostia of the coronary arteries. In thisembodiment the valve would have a sealing portion on the inlet side ofthe valve, the sealing portion would have an outside diameter to matchthe patients aortic root diameter. This diameter would range from about18 mm to about 38 mm. Multiple sized valves are required to accommodatediffering patient anatomies. The sealing portion of the valve may beexpandable or compliant to improve sealing and best conform to a widerange of patient anatomies. The length of the sealing portion is limitedby the position of the valve and the position of the coronary arteries,the length of the sealing portion may range from about 1 mm to about 5mm, preferably about 3 mm. The mid and outlet portions of the valve arepreferably between 30% and 90% the diameter of the native aorta. Thisallows sufficient room for blood to flow back around the valve andperfuse the coronary arteries. The valve may also incorporate asecondary retaining mechanism, securing the outlet or mid portion of thevalve beyond the coronary arteries

Alternatively, the valve can be replaced by a pump similar to a devicedesigned by Medtronic known as a Hemo Pump, which is placed in theaorta. The pump moves blood out from the ventricle into the aorta,serving the function of both the native aortic valve and the contractingleft ventricle. The pump may consist of a screw type pump actuated by arotating shaft, where the motor is located outside the body. The inletof the pump located on the distal end of the catheter may optionally beisolated from the outlet of the pump by a balloon. The balloon inflatesbetween the outside diameter of the pump and the inner diameter of theaorta, in a location between the pump inlet and the pump outlet.Alternatively a pump using two occlusion balloons, both between theinlet and the outlet of the pump could isolate an area between theballoons for treatment. The valve removal procedure could take place inthis area.

The temporary valve designs described by Moulolupos and Boretos in U.S.Pat. Nos. 3,671,979 and 4,056,854 respectively, include umbrella valvedesigns that allow the blood to flow in one direction between the valveand the wall of the aorta. The valves prevent flow in an oppositedirection as the valve seals against the wall of the aorta. These valvescan be attached to a temporary valve catheter and adapted for use withthe present invention.

Other valve designs are also possible for a temporary valve including aball and cage valve, a tilting leaflet valve, bi-leaflet valve a reedtype valve, a windsock style valve, a duckbill valve, or a tricuspidvalve. In addition to these valves made from synthetic materialsincluding polyurethane or tissue valve may also be utilized. Commonlyused in permanent valve replacements valves constructed from bovinepericardium or porcine aortic valves, are adequate. To produce a lowprofile percutaneous device the preferred embodiment is a thin flexiblepolymer valve of either a duckbill design or umbrella valve design.

The temporary valve should be placed in such a way that it can be easilyremoved at the end of the procedure and also in such a way that theoperator has access across the valve for performing the remaining steps.A guidewire or catheter lumen placed through the valve or around thevalve before the valve is positioned in the body allows the requiredaccess for downstream procedures.

Alternatively an inflatable structure may be used. The inflatablestructure provides the advantage of improved sealing characteristicswith the vessel wall, and the inflatable structure may produce a lowerprofile device with some valve designs. The inflatable valve structurecould be designed to be recoverable using wires as described in previousdirect flow disclosures for permanent valve replacement devices, aninflatable prosthetic valve was first described by Block in U.S. Pat.No. 5,554,185 and is also described herein. The inflatable structurepreferably inflates to an outside diameter between about 18 mm and about35 mm.

In another embodiment, the temporary valve structure is a recoverableself-expanding stent. The stent could be a Z-stent formed from wiressegments shaped into rings or a coil. Alternatively the Z-stent could becut from a tube using a process like laser cutting. With a Z-type stentcareful design of the stent shape is required to make the stentrecoverable. It must be ensured that no crown hangs up on the recoverysheath. One method to accomplish this is to attach each crown to thecrown of the next stent segment by welding, fusing or other joiningtechniques. Or the stent could be braided from wires in a design similarto a Wall Stent as produced by Boston Scientific. The material for thestent is preferably a superelastic material such as nitinol.Alternatively a material with a relatively high yield strength and/or arelatively low modulus of elasticity, such as a cobalt chrome alloy, ortitanium, could be used. These non superelastic materials are mostappropriate for use in a stent manufactured by a braiding process.

In another embodiment, the structure for the temporary valve 520consists of an unwrapable structure, similar to the structure describedby Yang in U.S. Pat. No. 6,733,525 or as described herein. The structureis delivered in its wrapped position. After the structure is positionedthe structure is unwrapped and expanded to its final diameter.

In general, any of a wide variety of valve structures may be utilizedfor the temporary valve in accordance with the present invention. Sincethe temporary valve is only intended to remain functional at anintraluminal site for a relatively short period of time (e.g. less thana few hours), the temporary valve of the present invention is notplagued by many of the deficiencies of prior permanent implantablevalves (thrombogenicity, efficiency, durability, etc.). Thus, valvedesign can be selected to minimize the initial crossing profile andoptimize removal.

For example, in the example described previously in which a valve issupported by a Z-stent structure, each of the proximal apexes of thestent may be attached to a pull wire, which merge into a common axiallymoveable control wire which runs the length of the temporary valvedeployment catheter. Following transluminal navigation to the desiredtemporary valve site, an outer sheath may be proximally retractedrelative to the control wire, thereby enabling the stent and valve to bedeployed from the distal end of the catheter. Following completion ofthe procedure, the temporary valve may be removed by applying proximaltraction to the control wire and/or distal force on the outer sheath.The plurality of control filaments will cause the Z-stent to collapse,as it is drawn back into the tubular sheath.

Thus, the temporary valve of the present invention is preferablypermanently attached to its deployment catheter. In this regard, theterm “deployment” refers to the conversion of the temporary valve from areduced cross sectional profile such as for transluminal navigation, toan enlarged cross sectional profile for functioning as a valve in avascular environment. However, at no time does the valve become detachedfrom the deployment catheter. This eliminates the complexity of snaringor otherwise recapturing the temporary valve, for retraction into acatheter. Alternatively, the present invention may be practiced by theuse of a detachable temporary valve, which must be captured prior toremoval.

The preferred temporary valve is therefore preferably carried by anelongate flexible catheter body, having a proximal control for advancingthe valve into a functional configuration, and retracting the valve intoa collapsed configuration for transluminal navigation into or away fromthe temporary valve site. Activation of the control to retract the valveback into the temporary valve catheter does not necessarily need topreserve the functionality of the valve. Thus, proximal retraction ofthe valve into the temporary valve catheter may involve a disassembly,stretching, unwinding, or other destruction of the valve if that isdesirable to facilitate the step of removing the temporary valve.

Although tissue valves may be used for the temporary valve in accordancewith the present invention, due to the short duration of the intendedworking life of the valve, any of a variety of polymeric valves may beadapted for use in the present context. Polymeric membranes may beconfigured to mimic the leaflets on a normal heart valve, or may beconfigured in any of a wide variety of alternative forms, as long asthey are moveable between a first, open configuration and a second,closed configuration for permitting blood flow and essentially only asingle direction. Thus, polymeric membranes may be formed into any of awide variety of flapper valves, duck bill valves, or otherconfigurations.

Regardless of the valve leaflet construction, the temporary valve may besupported by an inflatable cuff as has been disclosed elsewhere herein.The temporary valve deployment catheter is provided with an inflationlumen extending between a proximal source of inflation media and adistal point of attachment to the inflatable cuff. Once positioned atthe desired site, the temporary valve may be released such as byproximal retraction of an outer delivery sheath. Inflation media maythereafter be expressed from the source to inflate the cuff to enablethe valve and provide a seal with the vessel wall. Following theprocedure, the inflation media is aspirated out of the cuff by way ofthe inflation lumen 318 to deflate the cuff, and the temporary valve iswithdrawn from the patient.

Alternatively, the temporary valve may take the form of an inflatableballoon, with an inflation cycle which is synchronized to the heart beatso that it is deflated to permit forward flow but inflated to inhibitreverse flow in the artery.

An embolic protection filter may be mounted to the temporary valve or tothe temporary valve structure. The filter may be attached to the outletsection of a duckbill type valve. Alternatively the filter may bemounted on its own support structure.

With the temporary valve deployed as shown in FIGS. 57D and 57E, afilter or embolic protection device 522 may be used during the procedureof implanting a percutaneous valve. Several methods of embolicprotection are possible as described above. In the illustratedembodiment of FIG. 57F, a filtering basket 524 is placed down stream ofthe temporary valve 520 as shown, the basket 524 catches any debris thatis embolized or cut from the native valve (see FIG. 57G) and the basket524 is then recovered.

A trapping size of about 35 to 250 micron and may be treated with ananti-thrombogenic coating to prevent clotting. A basket of similardesign could be mounted to the catheter shaft of a device designed forpercutaneous treatment of a coronary valve, in a case where the valve isapproached from a retrograde direction. In an application where thedevice is placed in an antegrade direction, a larger version of aconventional wire based embolic protection device could be used.

In an application for aortic valve treatment it may be desirable toplace the embolic protection very close to the annulus of the valvebecause the ostia of the coronary arteries are very close to the areabeing treated. In a balloon, valvuloplasty used as a pretreatment forvalve replacement or alone as an independent therapy, the embolicprotection filter may be attached to the proximal end of the balloon orto the catheter shaft very near the proximal end of the balloon,specifically within 1 cm of the proximal end of the balloon. The filtercould be positioned similarly on a catheter for the delivery of apercutaneous prosthetic valve, this configuration is especiallybeneficial for a balloon expandable prosthetic valve.

An alternative method of embolic protection applicable to a balloonvalvuloplasty or implantation of a percutaneous prosthetic valve bymeans that prevent flow through the aortic valve is described asfollows. Flow is occluded in a position at the treatment site or,preferably beyond the treatment site, in either a retrograde orantegrade direction. The treatment is performed. The treatment site isdisengaged from the device. The treatment area is aspirated. Because theflow is prevented by the occlusion the embolic material does not travel.The occlusion is then removed. The preferred embodiment for an aorticapplication is a valvuloplasty balloon with dual balloons. A largerdistal balloon is inflated within the ventricle. The balloon is pulledback so that the aortic outflow is obstructed, the balloon is sized sothat it is significantly larger than the aortic valve. The secondsmaller diameter balloon located immediately proximal to the firstballoon is then inflated to dilate the valve annulus. The second balloonis then deflated and the entire area aspirated with an aspirationcatheter. The first balloon is then deflated to restore aortic outflow.Alternatively, there may be a tube central to these balloons providingflow while this operation in occurring. This would be a limited by-passof oxygenated blood around the area being decalcified. During thisby-pass, a cutting mechanism may be introduced where as the valve andcalcium may be mechanically removed. Examples of cutting mechanismswould include a rotating burr, an oscillating pin and die to punch thematerial out in segments or ultrasound energy to fragment the materialfree for aspiration removal. It may be necessary to additionallycanulate the coronary arteries to continue flow to these criticalvessels.

The system could further contain a perfusion lumen to reintroduce theleft ventricular outflow in a location that does not cause the movementof blood in the area of the aortic root. For example blood could bereintroduced in the coronary arteries or in the aortic arch or in thecarotid arteries.

It may also be possible to have the filter device 522 mounted to thedelivery catheter and actuated by the handle to open and close thefilter to the vessel wall. This device would be placed between theaortic valve and the great vessels in the arch. A secondary cathetersystem could also be used to filter debris from the aorta and deliveredfrom another vessel to the arch. This filter could also be attached tothe temporary valve assembly providing filtration protection with valvesupport as the native valve is removed or decalcified. A filter couldalso be mounted to the excision tool protecting the down stream vesselsfrom emboli. By protecting each individual vessel such as the carotids,great vessels, and the aorta separately, devices would be required ineach of these vessels to protect them from emboli. These filters couldbe a simple windsox style as seen by EPI (Boston Scientific) and couldrecover the emboli through a catheter. Other systems for filtrationinclude the Percusurge device sold by Medtronic where balloons protectthe area of interest and aspiration withdrawals the emboli.

Filtration devices may be set directly on the calcified aortic valve toprevent any material from escaping. This filtration device may be madefrom a woven or braided wire such as Nitinol or stainless steel, MP35N,polymeric fibers or other suitable material commonly used in medicaldevices. The materials may be composed of round, oval or flat ribbonmaterial. This may provide benefits when designing low profile device.These wire would be have cross sectional diameters ranging from0.001-0.030 inches. These wires may be supported by larger extensionwires to hold the filter material open as seen in. The filter mayrequire a support structure such as a stent or series of struts toprovide dimensional integrity. This stent structure could be a commonZ-stent or an inflatable structure to hold the filter open and sealed tothe valve base or vessel wall. The support structure would be expandedor deployed by exposing the device from a sheath or by activelyproviding a force to move the structure from a beginning shape to afinal shape. Housed in a catheter for delivery, the device would beconstrained to a small cross section and expand to a larger crosssectional diameter or area as allowed. The deployed device would have ageneral conical shape with the open large diameter facing down or towardthe valve. The opposite end would come together at the catheter and beretrievable by the introduction catheter or a second retrieval catheterto remove any debris captured. These catheters may have a diameter ofabout 8-24 French. The filtration material could be located inside oroutside the support structure depending upon what flow characteristicswere required. For instance, if the filter material was located on theoutside of the support structure the filter may be in contact with thecoronary ostia. It may be more desirable to have the filter material onthe inside of the support structure holding it away from the ostia ofthe coronary arteries. The filtration would trap particles from about35-250 microns in size and allow adequate flow through the aorta. Thedistal portion of the filter may have a ring or template at the distalend to allow for a patterned removal of the native aortic valve. Thedistal portion would fit between the aortic wall of the sinus and thecalcium deposits to be removed. The template would provide a patternthat may be traced by a removal tool as described in paragraphs above.By using a template the pattern would be close to the native healthyorifice. An acceptable cross sectional area would be about 2-3 cm². Thiswould provide adequate room to place a new valve and provide the patientgood hemodynamic flow. This template could be as simple as a guideprovided by a wire ring or a pattern with three arches as seen in ahealthy valve similar to a clover. It may however be simpler to providea round hole than a complex shape to begin. This template may be aboveor below the native valve and may require more than one shape and orsize.

Another design for a filter is to utilize a braided Nitinol stent thatwill provide support to the filter material but is still recoverableinside the catheter. In this embodiment, the filter material would beinside the braided structure and the braid would be in contact with theaortic wall. This would provide a seal between the filter device and thevessel directing flow through the filter element and allowing thecoronary arteries to be patent

After the temporary valve 520 and embolic protection filter 524 are inplace, a debulking or valve removal step is performed as shown in FIGS.57F-H. If possible, a guidewire may be advanced across the native valve.In some severely calcified native valves it may not be possible orpractical to advance a wire across the valve. In these cases a new lumenmay be formed through the valve. This can be done using a sharp wireneedle or a heated wire cutting tool, or a rotating drill type cuttingtool. A centering device may be used to ensure that the new lumen iscreated near the center of the native valve. Designs for centeringdevices known in interventional cardiology for the treatment ofchronically occluded arteries may be used. These devices typicallyinclude a centering balloon. Alternatively an expandable wire basket maybe used to center the wire while maintaining flow. An expandable basketcould be cut from a superelastic hypotube such as a nitinol hypotube.One basket design includes a short uncut section of tube at both theproximal and distal ends this tube segment is about 1 to about 3 mm inlength. The proximal and distal tube sections are connected by at leastthree struts. The struts are from about 30 to about 60 mm in length, andmay be stabilized to each other by one ore more connectors along theirlength. The tube is then heat set or otherwise formed so that the middleportion is expanded to between 18 mm and 35 mm. The proximal and distaluncut hypotube sections support a central lumen for guidewire access,while the struts push out against the vessel walls to center the device.

After wire access has been gained it still may be difficult orimpossible to pass some embodiments of the cutting device across thestenossed native valve. If necessary a preliminary cutting step may beperformed to enlarge the valve opening sufficiently that a secondcutting device may be inserted. In one embodiment the primary cuttingdevice includes a rotating burr centered on a guidewire. The burr ismounted to a small flexible hypotube or solid shaft, which is spun by amotor outside the body. Preferably the hypotube has an inside diameterof 0.014 to 0.040 in and the shaft has a diameter of about 0.010-0.030inches. The rotating burr preferably has an outside diameter slightlylarger than the secondary cutting tool this is preferably in a range of2 to 6 mm diameter. A similar rotating burr device is marketed by BostonScientific, under the trade name Rotoblader, for the treatment ofstenotic arteries.

A cutting device of this design could also be used to open the calcifiedvalve to the desired diameter. In this case a larger burr may be usedranging in diameter from about 3 to about 9 mm in diameter. A steerablecatheter may be required to center the newly enlarged opening in thenative anatomy. A steerable catheter may consist of a flexible elongatetube with a pull wire located off center in at least a portion of theelongate tube. When tension is applied to the pullwire, it causes thecatheter to bend in the direction to which the wire is offset. Multiplepullwires may be used to allow the catheter to be steered in multipleareas or directions. The catheter my also be manufactured with apreferred bending plane, allowing even a centered pullwire to steer thecatheter, and providing more precise control of the catheter shape. Thecatheter is preferably of an outside diameter between 3 mm and 9 mm.

Several embodiments of cutting devices are possible some of which aredescribe above. In one embodiment, the cutting device 530 consists of atool that pushes or pulls a sharpened punch into a die as described withreference to FIG. 53A. This cuts segments of calcified tissue away fromthe valve annulus and pulls them back into the catheter shaft. Fromthere suction may optionally be applied to extract the calcified tissuefrom the body through a catheter. This design has the advantage ofproducing a minimum of embolic debris, because most of the tissue isforced into the catheter shaft. Preferably the cutting die ismanufactured from a hardened pin ground at an angle so that the cuttingforces are primarily piercing the material first with a high force persquare inch. The cutter is preferably ground at an angle between 20 and80 degrees from the axial direction of the pin. Secondary angles mayalso be ground on the pin near the pint formed by the primary grindingangle. This minimizes the force required to start the cut. Preferablythe pin diameter is between 3 mm and 10 mm.

Alternatively a similar cutting device could be used where the cuttingportion consists of a rotating cutter. The cutter is pulled back throughthe die portion forcing the material into the catheter shaft in asimilar manner to the device described above. The rotating edge of thecutter may be sharpened to an edge to minimize embolic material as muchas possible or may be serrated to maximize the cutting ability of thedevice. This device is very similar in function to devices commonly usedfor DCA or directional coronary atherectomy. Typically DCA devices cutin a push mode, capturing the cut out section in a cavity near thedistal tip of the device. The devices described above operate in a pullmode, which allows the cut out material to be evacuated out the cathetershaft or fill a larger area within the catheter shaft. However eithercutting device described could be manufactured to operate in a push moderather than a pull mode. It may be desired to have the helix directionpull the material back or proximally to the catheter handle. This wouldallow for convenient removal of the debris from the body.

The cutting device may include a device to engage the cutting portion ofthe device to the tissue. In one embodiment a balloon possibly aperfusion balloon is attached to the non-cutting side of the device. Asthe balloon is inflated the cutter is moved laterally to engaged intothe tissue. To maintain flow out of the heart the balloon inflation andcutting may be accomplished during the time that the aortic valve wouldbe closed. This could be synchronized to the patients heart rate byechocardiography or similar sensing techniques or the patient could beplaced on a temporary pace maker and the pacemaker output could be usedto time the inflation of the balloon. The inflation media could be aliquid or a gas. A gas such as helium or CO2 would allow the quickestinflation time through a small lumen. Helium would provide an evenquicker inflation time than CO2, however CO2 may be better dissolved inthe blood in the event of a balloon burst.

Preferably the engagement method allows flow to pass around theengagement device as shown in FIG. 53A. One way to accomplish this iswith a single or plurality of metal straps as described above withreference to FIG. 53A that expand out from the catheter against thenative valve. The straps may be made to bow out from the catheter shaftby moving the mounting points of the straps towards each other, or bysliding the straps through the proximal section of the catheter.Alternatively the straps may be made self expanding and be constrainedby a sheath or other means, during delivery. A self expanding sheatheddevice may consist of other geometries besides a simple strap. Forexample the expanding device could be formed from a braided mesh similarto a recoverable self expanding stent. These straps would be about0.005-0.020 inches in cross section and have a length of about 40-80 mm.

Another engagement method that allows flow past the catheter includes asteerable catheter mechanism. The device can be bent in such a way thatthe window of the cutting device is pushed against the tissue, whilethis force is opposed by a section of the catheter bushed against tissuein an opposite direction. A DCA device marketed by the company Foxhollowuses this mechanism to engage tissue.

The engagement means may be adjustable to a predetermined range of sizesfrom the catheter handle. The cutting tool is advanced or retracted intothe annulus and successive cuts are made by the operator. The cathetermay be rotated slightly between each cut. Once the new annulus is cutout large enough for the engagement means to pass through the annulusthe operator knows that the annulus has been enlarged to a size thatcorresponds with the adjustment, or size of the engagement means. Ifthis is a sufficiently large cross sectional area for adequate flowafter the permanent prosthetic valve is implanted, then the cuttingdevice may be removed. If a larger annulus is desired the engagementmeans may be adjusted or replaced with a larger size, and the processrepeated. If the distal end of wire straps are attached at the distalend of the cutting device and the proximal end of the wire straps areattached to the distal end of a sheath mounted over the cutting toolshaft, then the advancement of the sheath will cause the wire straps tobow out and engage the tissue. The distance that the sheath is advancedcorresponds to the diameter that the engagement mechanism will passthrough. Markings on the cutter shaft show the operator what diameterthe engagement means is expanded to. Preferably the engagement means isexpandable to at least about 2 cm. This provides an effective orificearea over 3 cm².

The cutting device 530 may include a lumen for contrast or therapeuticagent injection. The injection of contrast allows the operator tovisualize the size and position of the cut out area relative to theaortic root and the ventricle, under fluoroscopy, MRI, NMR or otherimaging techniques used in interventional cardiology. The injection of atherapeutic agent may be used to have any desired effect on the heart orventricle. Certain therapeutic agents such as antibiotics may aid inreducing the risk of endocarditis or in the treatment of a valve damagedby endocarditis. Other therapeutic agents may increase or decrease theheart rate or hearts output as desired by the physician. The diameter ofthe inflation lumen is preferably between 0.010 and 0.060 in. indiameter.

As the valve 34 is being removed imaging the procedure is important. Theoperator must be able to visualize the position of the cutout relativeto the aortic wall and the aortic root. Two-dimensional imagingtechniques such as fluoroscopy need to be performed on multiple axis toallow the cutting procedure to be performed safely. The operator must becareful not to cut through the aortic wall or through the ventricle.Electrical conduction paths near the annulus such as the bundle of hismay require special attention and care. The area between the anteriorleaflet of the mitral valve and the aortic valve must not be damaged,and the mitral leaflets and chordae must be avoided. To visualize theseand other obstacles during the procedure any number of common imagingtechniques may be employed either during the procedure or prior to theprocedure in a road-mapping step. Echocardiography may be employed inone of several forms to image the necessary areas. TEE or transesophageal echocardiography may be particularly useful in imaging thevalve area before the procedure begins and during the procedure as well.TTE may also be used with the benefit of being less invasive to thepatient, but it is limited by a reduced image quality and the fact thatthe operator's hand must be near the patient's chest. This makes thesimultaneous use of fluoroscopy and other imaging techniques unsafe forthe operator. During the procedure fluoroscopy or MRI or NMR or similarimaging techniques may be used to visualize the size and shape of thenewly cut out opening and the position of the opening relative to allthe relevant structures of the native anatomy.

The cutting device 830 could be actuated by a simple lever type handlemoving the cutter in either a proximal or a distal direction as thehandle is squeezed. In addition the handle could contain a rotationalswivel or union that allows the catheter to be rotated while the handleis held in a fixed position. Further, the function of the catheterrotation could be incorporated into the actuation of the handle. Thehandle mechanism could be designed or adjusted sot that the catheterrotates a predetermined amount each time the cutter is actuated. Thiscould be accomplished with a simple cam and sprag mechanism, or using astepper motor. The actuation of the cutting mechanism could also bepowered electronically or pneumatically to minimize operator fatigue andto prevent the overloading of the device. In this case the operatorwould simply depress a button to actuate the cutting function. Thehandle may also contain an aspiration lumen to assist in the removal ofdebris from within the catheter shaft, and an injection lumen to injectcontrast media or a therapeutic agent, or a fluid such as saline. Othermeans of providing energy to the device include an impact or momentumdrive where a high velocity rate would contact the area to be removedproviding a high degree of force to the calcific valve. Drive orpropultion methods may include a gaseous discharge or chemical reactionto generate a hydraulic force to drive an object into or through thecalcified valve. Other predictiable forces may include preloading aspring mechanism and releasing the energy stored to drive an object intoor through the calcified valve.

The valve could also be cut out in sections using a laser or heatedwire. Severely calcified areas could be broken up with CavitationUltrasound energy, prior to removal with a cutting tool or the calcifiedareas may be broken up with ultrasound and the debris captured in afilter. Similarly a chemical compound could be used to dissolve or breakup the calcium.

With reference to FIGS. 57I-57L, the valve implantation step includesthe installation of an inflatable valve 100 as described above or anystent based valve such as Edwards/PVT, CoreValve's self-expandingsystem. This step is described in previous filings by Lashinski fromDirect Flow Medical and by Anderson from PVT/HeartPort both ofCalifornia.

With reference now to FIGS. 57M-57O, as a final step in the illustratedembodiment, the two items to be removed after successful implantation ofthe new valve are the filtration device 522 which may hold emboli ordebris and it's delivery catheter. This step may require aspiration andor suction to capture any items not trapped within the filter. Once thefilter moved through the temporary valve 520, the filter 524 may need tobe redeployed to capture any particles that the temporary valve 520 mayhold or dislodge during removal. Once the temporary valve 520 is eitherdeflated or drawn back into the sheath, the filter 524 and it's deliverysystem may be removed leaving the new valve 100 functioning properly.

The illustrated embodiment provides a method of implanting apercutaneous prosthetic valve assembly, where the outflow tract is notblocked at any time during the implantation process. In heart failurepatients, blocking the aortic output can have serious consequences, suchas death. Another less significant problem with blocking aortic outputis the contracting ventricle can exert significant pressure on thedevice, making positioning very difficult, and possibly forcing thedevice away from the desired location before it is completely deployedor anchored. To overcome this issue in some cases patients have beenrapidly paced. By increasing the patients heart rate to such an extentthat the heart does not effectively pump blood. This may not be requiredduring the implantation of this inflatable device.

In contrast, devices such as those disclosed in Andersen family of USpatents (U.S. Pat. Nos. 5,411,552 6,168,614 6,582,462) result in thecomplete or nearly complete obstruction of the aortic valve duringdeployment. For example as a balloon expandable valve structure isexpanded the balloon blocks the aortic output. In one embodimentAndersen describes the use of multiple balloons to deploy the valve, aswas common with a balloon valvuloplasty. Using multiple balloons wouldprovide a very small path for fluid to flow between the balloons whenthe balloons are fully inflated to a pressure high enough that they takeon their natural generally round cross section. However when theballoons are partially inflated or during the inflation process themultiple balloons conform to and occlude the lumen, resulting incomplete or nearly complete blockage of the outflow tract.

The self-expanding valve support structures disclosed in Andersen andLeonhardt (U.S. Pat. Nos. 6,582,462 and 5,957,949) also block aorticoutflow as they are deployed. As the sheath is retracted from the distalportion of the device the device opens and begins to conform to thenative vessel. The portion of the valve structure designed to seal tothe valve annulus or other portion of the native anatomy comes incontact with the native anatomy. At the same time, the proximal portionof the device is still restrained within the deployment catheter,preventing the valve from opening. At this stage of deployment thedevices effectively block all aortic output.

The simplest extension of existing technology to allow implantation of aprosthetic valve without blocking flow is the use of a perfusion balloonwith a balloon expandable support structure. The perfusion balloon wouldhave a lumen through the balloon large enough to allow significantperfusion through the balloon during deployment. Perfusion balloontechnology is well developed, and known. Wasicek et al describe aperfusion balloon catheter is U.S. Pat. No. 6,117,106

Using a self-expanding valve support structure it would be possible tomaintain flow past the valve using a tube section placed through theaffected valve, outside the self expanding support structure. After theself-expanding support structure is completely deployed the tube sectioncould be withdrawn. The tube section is longer than at least the sealingportion of the self-expanding valve support structure, and preferablyattached to an elongate member to allow its withdrawal. Alternativelythe tube section could be located inside the valve support structure. Inthis case the tube section would allow fluid (usually blood) to flowinto the deployment catheter. Perfusion holes in the deployment catheterwould allow blood to flow out into the native conduit.

Relating to the current inflatable prosthetic valve or cast in placesupport structure described herein, a different deployment procedure isused which allows outflow to be maintained. This deployment method couldalso be used with some self-expanding percutaneous valves. Thedeployment method is described as follows for an aortic valvereplacement. The procedure could be easily adapted to any other coronaryvalve. The deployment catheter is advanced across the aortic valve. Theprosthetic valve and inflatable cuff are unsheathed in the ventricle,but remain attached to the deployment control wires. The distal end ofthe inflatable cuff is inflated. The sheath is retracted far enough thatthe deployment control wires allow the prosthetic valve to function. Thedevice is then withdrawn across the native valve annulus. The device isthen fully inflated. The valve function may be tested using variousdiagnostic techniques. If the valve function is sufficient the inflationmedia may be exchanged for the permanent inflation media. The deploymentcontrol wires and the inflation lumens are then disconnected and thecatheter withdrawn. In this procedure the key to maintaining the outflowtract is the use of deployment control wires. The deployment controlwires allow the device to be moved an appreciable distance from thedeployment sheath before the device is permanently positioned in thedesired location. Other deployment control devices could be used to havesimilar effect. For example a sheath used as a shear barrier between theretractable sheath and the implant having longitudinal slots could beconfigured to produce a similar function. It may be desirable topredilate the native valve annulus with a balloon before deviceimplantation. This may allow for a larger effective orifice area toimplant the device and precondition the valve area. Secondarily, anadditional dilatation may be desired after implantation to ensure thedevice is apposed to the wall of the annulus and seated properly.

The current percutaneous valve replacement devices do not provide ameans for testing the function of the valve before committing to theposition of the valve. These devices are deployed at a location and ifthe location was a wrong location or if the valve does not have a goodeffect, the valves can-not be removed. The present invention includes amethod of valve implantation consisting of the steps of positioning thevalve, enabling the valve, testing the function of the valve, andfinally deploying the valve.

Relating to the current inflatable prosthetic valve or cast in placecuff, a unique deployment procedure is used, consisting of the steps ofposition, enable, test, and reposition or deploy. This deployment methodcould also be adapted to a valve with a self-expanding support structureor to other implantable devices. The deployment method is described asfollows for an aortic valve replacement. The procedure could be easilyadapted to any other coronary valve. The deployment catheter is advancedacross the aortic valve. The prosthetic valve and inflatable cuff areunsheathed in the ventricle, but remain attached to the deploymentcontrol wires. The distal end of the inflatable cuff is inflated. Thesheath is retracted far enough that the deployment control wires allowthe prosthetic valve to function. The device is then withdrawn acrossthe native valve annulus. The device is then fully inflated, enablingthe valve to function. The valve function may be tested using variousdiagnostic techniques. If the valve function, sizing or securement isnot sufficient or ideal the valve may be partially deflated, andadvanced or retracted, and then reinflated or the valve may be fullydeflated and retracted into the deployment catheter or another slightlylarger catheter, and removed. Once a valve is positioned, sized andsecured acceptably or ideally the inflation media may be exchanged for apermanent inflation media, which may jell, set or cure. The inflationcatheters and deployment control wires are then disconnected and thecatheter removed, fully deploying the valve.

If the technology from a known self-expanding recoverable stent isadapted to a valve support structure, the stent is only recoverable froma partially deployed state. A self-expanding support structure of alength sufficient only to support and retain the valve would not allowtesting of the valve function, until the valve was fully deployed. Thisis because the proximal portion of the support structure containedwithin the device would prevent normal function of the valve. A proximalextension of the support structure could be added to act as a deploymentcontrol device allowing the valve function to be tested in aconfiguration where it is still possible to remove or reposition thevalve. The proximal extension could be a continuation of the braided orlaser cut stent structure, provided that the cell structure is openenough to allow blood flow through the stent. In an aortic valveapplication the required length of the proximal extension would mostlikely extend beyond the ostia of the coronary arteries. In this casethe shape of the stent structure may be designed to permit unobstructedflow to the coronary arteries or to permit adequate flow to the coronaryarteries. Another possibility is to design the proximal extension sothat it acts as multiple individual wires. This could be done by lasercutting or by changing a braid pattern. This would also allow theproximal portion of the implant to act as a deployment control device.

A method for recapturing a self-expanding stent is described by Johnsonet al in U.S. Pat. No. 5,817,102, as follows.

There is provided an apparatus for deploying a radially self-expandingstent within a body lumen. The apparatus includes a stent confiningmeans for elastically compressing a radially self-expanding stent into adelivery configuration in which the self-expanding stent has a reducedradius along its entire axial length. The apparatus includes an elongateand flexible stent delivery device having a proximal end, a distal endand a distal region near the distal end. The distal region is used indelivering the radially self-expanding stent into a body lumen, and inpositioning at a treatment site within the body lumen with the stentsurrounding the delivery device along the distal region. The proximalend of the delivery device remains outside of the body. An axialrestraining means is disposed along the distal region of the deliverydevice. A control means is operable associated with the delivery deviceand the confining means. The control means moves the confining meansaxially relative to the delivery device toward and away from aconfinement position in which the confining means compresses theself-expanding stent into the delivery configuration, and urges thestent into a surface engagement with the axial restraining means. Therestraining means, due to the surface engagement, tends to maintain theself-expanding stent axially aligned with the deployment device as theconfining means is moved axially away from the confinement position torelease the stent for radial self-expansion.

Preferably the stent delivery device is an elongate and flexible lengthof interior tubing, with a central lumen for accommodating a guidewire.The stent confining means can be an elongate and flexible length oftubing, having a lumen for containing the interior tubing. The second(or outer) tubing surrounds the stent to confine it.

The preferred axial restraining means is a low durometer sleevesurrounding the interior tubing along the distal region. If desired, anadhesive can be applied to an exterior surface of the sleeves.Alternatively, the axial restraining means can consist of severalelongate strips disposed along the distal region, with adhesive appliedto radially outward surfaces of the strips, if desired.

In either event, so long as the exterior tubing surrounds the stent toradially compress the stent, it also maintains the stent in surfaceengagement with the sleeve or strips. As the exterior tubing is axiallywithdrawn to allow part of the stent to radially self-expand, the restof the stent remains confined against the sleeve or the strips. As aresult, the stent does not travel axially with the exterior tubing.Rather, the stent remains substantially fixed in the axial directionwith respect to the interior tubing. This structure affords severaladvantages. First, the interior tubing can be used as a means topositively maintain the radially self-expanding stent in the desiredaxial position during deployment. The interior tubing can itself beemployed as a reliable indicator of stent position, both prior to andduring deployment. Further, should the need arise to retract the stentafter a partial deployment, the outer tubing can be moved back into theconfinement position, without tending to carry the stent along with it.

The current percutaneous valve replacement devices are not removable orrepositionable. These devices are deployed at a location and if thelocation was a wrong location or if the valve does not have a goodeffect, the valves can not be removed, recaptured or repositionedpercutaneously. The present invention includes a method of implantationfacilitating percutaneously repositioning, recapturing and/or removing,a prosthetic valve

A balloon expandable support structure is more difficult to makerecapturable, repositionable or removable. One method would be to use ashape memory alloy, such as Nitinol. In this case if Nitinol was used itwould be in the martensitic phase at body temperature. MartensiticNitinol is not superelastic, but soft and conformable. It would besomewhat suitable as a balloon expandable support structure material,except the yield strength is very low. This requires relatively thickcross sections to be used. The balloon expandable support structure isdeployed in any way desired, such as by the methods described inAndersen. If the location or performance of the valve is not acceptablethe support structure may be caused to contract by changing itstemperature, causing it to return to its preset “remembered” shape,which in this case is a smaller, radially collapsed shape. Thetemperature controlling media could be a fluid such as saline, and couldbe delivered while a catheter or balloon is inserted through the supportstructure. This would cause the valve and valve support structure tocollapse down on the balloon or catheter allowing removal or possiblyredeployment. Other shape memory materials are available, and may havemore desirable mechanical properties for use as a balloon expandablesupport structure. In some cases the biocompatibility of these alloys isnot known.

It would be possible to construct a self-expanding valve that would becapable of being recaptured. This could be done using technology fromrecapturable self-expanding stents. Typically these devices are braidedfrom a superelastic or high strength alloy and have relatively lowradial strength. As they are pulled back into a sheath they collapse ontheir diameter and lengthen facilitating recapturability. Not allbraided self-expanding structures are recapturable. To our knowledgethis technology has not yet been applied to valve support structures.

Relating to the current inflatable prosthetic valve or cast in placesupport structure, a different deployment procedure is used which allowsthe device to be repositionable recapturable, and removable. Thisdeployment method could also be used with some self-expandingpercutaneous valve support structures. The deployment method isdescribed as follows for an aortic valve replacement. The procedurecould be easily adapted to any other coronary valve. The deploymentcatheter is advanced across the aortic valve. The prosthetic valve andinflatable cuff are unsheathed in the ventricle, but remain attached tothe deployment control wires. The distal end of the inflatable cuff isinflated. The sheath is retracted far enough that the deployment controlwires allow the prosthetic valve to function. The device is thenwithdrawn across the native valve annulus. The device is then fullyinflated. The valve function may be tested using various diagnostictechniques. If the valve function, sizing or securement is notsufficient or ideal the valve may be partially deflated, and advanced orretracted, and then reinflated or the valve may be fully deflated andretracted into the deployment catheter or another slightly largercatheter, and removed. Once a valve is positioned, sized and securedacceptably or ideally the inflation media may be exchanged for apermanent inflation media which may jell, set or cure. The inflationcatheters and deployment control wires are then disconnected and thecatheter removed. This deployment method provides many advantagesincluding the ability to reposition recapture and remove the device.

In an alternative delivery method (surgical) transapical access wouldallow for the device to be placed in a less invasive surgical procedure.This may still be a beating-heart procedure but would limit the accessincision area. Through the apex of the heart a tube may be inserted tointroduce the device to the aortic valve from a antigrade approach. Thiswould allow the device to be placed and or moved in the same mannerpreviously described in a catheter delivery.

The prosthetic valve with inflatable cuff may also be deliveredsurgically. The inflatable cuff aids in sealing the valve to the nativeanatomy. A valve of this design may be placed in any coronary valveposition as well as in a vein, lung, ureter, or any area of the bodyknown to benefit from the implantation of a valve or flow controldevice. In one embodiment the native valve is sutured in place similarto known coronary prosthetic valves. The inflatable cuff is thenexpanded to form a tight seal with the native anatomy. In anotherembodiment the valve is placed in the desired location and the valve isexpanded. The valve is held in place by physical interference with thenative anatomy. The geometry of the implant may be similar to thepercutaneous applications for the inflatable prosthetic valve describedin previously.

The valve may be further secured by additional methods such as suturesor staples. The surgical procedure may also be performed in a lessinvasive manner, for example a smaller opening in the atrium or aortacould be used to implant the valve, because the valve attachment processis less critical. In another embodiment the valve may be implanted witha minimally invasive surgical device. A device of this design for anaortic valve application punctures the chest wall and the ventricularwall near the apex of the heart. The device is then advanced across thenative valve annulus and implanted in a manner consistent with thepercutaneous embodiments of the invention. This procedure may be guidedby echocardiography, angiography, thorascopy or any other appropriatevisualization method commonly known.

One Step Implantation

By deploying the device at the site in one step the native valve may beexcluded while the new valve is being placed. It is conceived that thedevice may have a shape similar to a tubular hyperbola to exclude theold valve by trapping it under the new structure during deployment. Thismay aid in patient comfort and safety if the vessel is not occludedduring implantation by a balloon deployed stent system. As the sheatheddevice is delivered via catheter through the vessel past the aorticvalve, it may be reveled or exposed by removing the sheath partially orcompletely and allowing proper placement at or beneath the native valve.Once in the vessel, the device may be moved proximal or distal and thefluid may be introduced to the cuff providing shape and structuralintegrity. It may be necessary to add or retract the fluid for properpositioning or removal. Once the cuff is positioned properly and thefluid is added creating the structure and sealing the device to thevessel wall, the delivery catheter may be disconnected and removedleaving the now functioning valve device as a permanent implant. Thedisconnection method may included cutting the attachments, rotatingscrews, withdrawing or shearing pins, mechanically decouplinginterlocked components, electrically separating a fuse joint, removing atrapped cylinder from a tube, fracturing a engineered zone, removing acollecting mechanism to expose a mechanical joint or many othertechniques known in the industry.

Two Step Implantation

It may be desirable to implant the valve structure in two steps. It isdesirable to attach the valve to the native tissue securely and withoutleaks. Also it is desirable to avoid blocking the flow of blood for along period of time. For these reasons it may be desirable to firstimplant a retention-sealing device as a first step and then as a secondstep implant the cuff with the valve attached. The retention-sealingdevice could be a stent like structure expanded in place or a ringshaped support structure where the valve is secondarily attached. Thering shaped structure could utilize the fluid inflation method asmentioned above and could be a separate system and catheter. It couldincorporate barbs for anchoring. It could also incorporate a sealingmaterial to help prevent blood from leaking around the valve. The devicecould incorporate a mechanism to attach the support structure to. Theretention mechanism could be a shoulder or a channel that the supportregisters in. Once in position, the deployment of the valve could takeplace as mentioned in the One Step Implantation description above

In an alternative embodiment a support structure, such as a stent isdelivered in one step and the valve is delivered in a later step. Thevalve is then attached to the support structure. The support structuremay be an expandable scaffold or stent designed to produce a physicalinterference with the native vessel. The support structure could alsouse the geometry of the native anatomy as described in otherembodiments, for

Deflate Balloons after Anchoring

In another embodiment the balloon inflation step is used to enable thedevice and the support structure and anchoring device are delivered in alater step. In one embodiment the support structure is a balloonexpandable stent. The stent is placed inside the inflated cuff. Thestent may also extend proximal or distal from the cuff. More than onestent can be used. Preferably a stent is placed proximal to the valveportion of the implant and a stent is placed distal to the valve portionof the implant, or a portion of the stent extends across the valve. Inone embodiment the balloons are left as part of the implant in adeflated state. The balloons are disconnected from the catheter by amechanism described in this application with the exception that thesealing feature is not required. Other detachment mechanisms are alsopossible. In another embodiment the balloon is removed from the deviceafter it is deflated. The balloon may be placed in a channel in the cuffand simply retracted after deflation. Alternatively the balloon may beattached to the implant with sutures designed to break as the balloon isinflated. After the balloon is inflated and deflated the balloon can beretracted.

Stent on Device

A method of delivering a valve attached to a cuff as a first step, anddelivering an expandable structure as a second step. The structure maybe a stent or an unwrapable band, engaged coaxially inside the cuff. Thecuff may be positioned using an inflatable cuff, where the cuff remainsinflated after the device is disconnected from the catheter. In thiscase the inflation serves the function of temporary securement and ofpermanent sealing. Alternatively the cuff may contain a removableballoon. In this embodiment the inflation provides a means of temporarysupport until the permanent support structure is deployed. Yet anotheralternative involves a valve and cuff assembly that contains noinflation provision. The cuff is held in place using deployment controlwires that are shaped in a way to cause the expansion of the prosthesis.The stent or expandable support structure is then delivered to aposition located coaxially within the cuff. The stent is then deployed,securing the device.

Creating Support Structure In Vivo

The present invention includes a method of creating a support structureinside the body of a patient. The preferred embodiment includesmanufacturing the support structure by a casting method. In this methodfluid is injected into a mold or cuff that is attached to the valve anddelivered percutaneously. The fluid then jells hardens or solidifiesforming the support structure.

There are other methods of manufacturing a support structure in vivo. Inone embodiment the support structure can be assembled from many smallsolid particles. The particles can be attached to one another by variousmeans, including a thread woven through the particles, in such a waythat when the thread is tensioned the thread and the particles form arigid structure. The particles could be attached to one another by asintering process, with an adhesive or by another method. The supportstructure could also be manufactured in place from wire, which is wovenand inserted into the shape of a support structure in vivo.

The support structure could also be manufactured in place using abiological reaction such as forming calcium deposits on the appropriateportion of the valve. The support structure could be assembled bynanomachines.

The support structure could also be manufactured from a fluid thatsolidifies jells or hardens that is not contained inside a mold. Thefluid could be applied to an area on the outer surface of the valve orthe inner surfaces oft the area where the valve is to be applied, invivo. The support structure could be manufactured from a material thatsolidifies hardens or becomes more rigid by the addition of a catalyst,heat, cold or other energy source. The material could be applied to theouter surface of the prosthetic valve before the valve is installed andthen activated in vivo. The support structure could be excited oractivated by an electronic energy. This source could also be activatedby magnets through a suspension fluid that solidifies in a magneticfield.

Attachment of Valve to Non-Structural Element

In the embodiments described above, the valve can be attached only to anonstructural element. In the preferred embodiment the nonstructuralelement is the sewing cuff or mold. The support structure is latermanufactured within the mold. Other examples of valves permanentlyattached only to nonstructural elements are possible. A valve could beattached to an unsupported tubular section of fabric. After the fabricgraft and valve are positioned in the patient a stent or other supportstructure could be deployed within the graft anchoring the graft inplace. The stent could utilize barbs or fangs to puncture the graft andanchor the devices solidly to the native tissue. The stent could also beplaced so that it only partially overlaps the graft. In this way barbsor fangs could be placed that do not puncture the graft. In anotherembodiment, rigid structural elements such as commissural support postsor barbs or anchors are attached to the cuff and delivered with thenonstructural element.

Radially Moveable and/or Flexible Tissue Supports

In accordance with another aspect of present invention, there isprovided an inflatable or formed in place support for a translumenallyimplantable heart valve, in which a plurality of tissue supports areflexible and/or movable throughout a range in a radial direction. Asused herein, a radial direction is a direction which is transverse tothe longitudinal axis of the flow path through the valve.

Valve and valve support design preferably accomplish a variety ofobjectives, including long term durability of the valve. The inflatablevalve support of the present embodiment can be optimized in a variety ofways, to enhance valve life. For example, except at its point ofattachment to the annulus, the wall and coaptive edges of the tissueleaflet preferably will not contact any structural components of theimplant or other tissue of the valve or surrounding environment. Suchcontact may result in premature wear and ultimately valve failure. Inaddition, upon valve closure, the tissue supporting elements of theformed in place support preferably allow for a controlled decelerationof the motion of the leaflets. This lessens the stress seen by theconnection points of the tissue to the structural elements. In manyvalve designs, these support elements are referred to as commissuralsupports.

The most common valve is a three cusp leaflet configuration wheresupport posts extend axially from the base of the valve in a downstreamdirection to support the tissue, creating a tricuspid valve. Preferably,under pressure, the leaflets will open and close with the stresses beingdistributed evenly about the structural element. In this tricuspiddesign, the forces upon closure of the valve are in an upstream axialdirection and radially inwardly on the valve. By allowing thecommissural supports to flex inward, the forces seen by the connectionbetween the tissue and the support element will drop and the longevityof the valve may be increased. In conventional surgical valves,deceleration or dampening of the closure force is accomplished by a wireformed stent or a polymer cast or machined to distribute the forcesevenly about the stent.

Forces experienced by the valve upon valve closure are on the order ofabout 15 grams per support post, and prosthetic valve testing may beaccomplished up to about 45 grams per support post, for a safety factorof about 300 percent. The supports are preferably movable in a radialdirection upon closure of the valve through a range, as is discussedbelow, to dampen the impact stresses on the valve.

Bending of the tissue supports may include not only flexure of thesupports but also flexure of the hoop or base of the valve support. Thismaximizes the distribution of stresses over the structural element,thereby lessening the stress concentrations at any one point or area.

The tissue supports (i.e., commissural supports) on the inflatable valvesupport of the present arrangement may be provided with a range ofradial direction motion in a variety of ways. Referring to FIG. 58, aninflatable support 107 is schematically illustrated, and has beendescribed in greater detail elsewhere herein. The illustrated inflatablesupport 107 has been simplified somewhat to illustrate the radial rangeof motion feature. For example, the illustrated inflatable support 107comprises a downstream support ring 108 a, and an upstream support ring108 b, but structure for maintaining the spacing between the supportrings and related inflation lumen have been omitted for simplicity.

The illustrated inflatable support 107 is configured for supporting avalve having a three cusp leaflet configuration, as has been discussed.Accordingly, the support 107 is provided with three tissue supports 200.Each tissue support 200 comprises a first inflatable strut 202 which isjoined with a second inflatable strut 204 at a downstream apex 206. Aswill be apparent to those of skill in the art, the first inflatablestrut 202 and second inflatable strut 204 may be separate components, ormay be a unitary tube, which is bent at an angle to form apex 206. Asmay be seen in FIG. 58, the apex 206 resides in contact with or adjacentthe radially inwardly-facing (lumenal) side of the downstream supportring 108 a.

Referring to FIG. 59, there is illustrated a top plan view of theinflatable support 107 of FIG. 58. As seen therein, each apex 206comprises a lumenal side 208 facing the center of the lumen and anablumenal side 210 facing radially outwardly from the center of theblood flow lumen. The downstream support ring 108 a may also beconsidered to have a lumenal side 212, facing radially inwardly. In FIG.59, the apex 206 is illustrated in a resting position, in which theablumenal side 210 of apex 206 is positioned in contact with or in closeproximity to the lumenal side 212 of the downstream support 108 a. Thismay be further seen in FIG. 59A.

As discussed briefly above, each apex 206 is capable of movement in aradial direction through a limited range of motion. As illustrated inFIG. 60, each apex 206 has been advanced radially inwardly away from thelumenal side 212 of the downstream support ring 108 a through a range ofmotion 218. The range of motion 218 may be engineered into the valve tohave a variety of limits, depending upon the desired valve performance.In general, apex 206 will be permitted to travel through a range of nogreater than about 3 mm, often no greater than about 2 mm, and, incertain embodiments, no greater than about 1 mm. The apex 206 ispreferably biased such that it is in contact with or in close proximityto the lumenal side 212 of downstream support ring 108 a as illustratedin FIGS. 59 and 59A, such that the downstream support ring 108 a servesas a limit on the range of travel for apex 206 in a radiallyoutwardly-facing direction.

In operation, forward flow of blood (systole) opens the leaflets in adownstream direction and may press the apex 206 against its outer limitof motion which may be contact with the downstream support ring 108 a.Upon valve closure, and under diastolic pressure, the apex 206 is forcedradially inwardly through the range of motion 218, to provide a spacingwhich may be seen in FIG. 60 or 60A. Upon valve opening, the apex 206 isallowed to flex radially outwardly, back into the position illustratedin FIGS. 59 and 59A. This configuration permits distribution of forceexperienced during normal valve operation, in a manner that may enhancevalve life.

The tissue support 200 may be configured in a variety of ways, toaccomplish a range of radial motion. For example, although the tissuesupport 200 is illustrated in FIG. 58 as having a first inflatable strut202 and a second inflatable strut 204, a third or fourth or moreinflatable struts may be joined at a single apex 206 to provide acommissural support 200. Alternatively, the tissue support 200 maycomprise only a single inflatable strut 202.

Alternatively, the tissue support 200 may comprise a non-inflatablecomponent, such as one or two or three or four or more axially-extendingsupport elements. The support elements may be solid elements, such aswire, ribbon, solid rod, or tubing stock which does not requireinflation for its structural integrity. Such support elements may bemovably connected or rigidly connected to the upstream support ring 108b in any of a variety of ways, depending upon the construction materialsand other design choices.

As an independent variable, the tissue support 200, whether inflatableor not, may permit a range of radial motion, either by flexing about adiscrete hinge point, or flexing about a force distribution, or bybending, or all of the above. Referring to FIG. 60A, there isillustrated a fragmentary cross-sectional view through the apex 206 of afirst inflatable strut 202. The apex 206 and strut 202 are illustratedas spaced apart from the downstream support ring 108 a by a distance214, such as during valve closure. In the illustrated embodiment, thefirst inflatable strut 202 remains substantially linear, indicating thatthe strut 202 has achieved movement by distributing torsional or bendingforces along its length and particularly in the vicinity of the upstreamsupport ring 108 b. This may be accomplished by using an inflation mediafor the first inflatable strut 202 which cures to a relatively rigidstate.

Alternatively, referring to FIG. 61, there is illustrated across-sectional view similar to FIG. 60A, in which the strut is insteadformed from a single strand solid element 215, such as a wire, orpolymeric extrusion, which may be configured in a sinusoidal patternmuch like that illustrated in FIG. 58. In this configuration, the metalor polymeric strut is flexible, although biased in the linearorientation, such that, as illustrated in FIG. 61, the strut bends alongits length to provide the range of motion 214.

As a further alternative, the tissue supporting strut 202 may be asingle element 218 extending in a downstream direction from the upstreamsupport ring 108 b, to a distal (downstream) end 216. In thisconstruction the tissue support 200 is only a single element, as opposedto an apex 206 at the junction of a first and second strut. The upstreamend of the tissue support 200 may be connected to the upstream supportring 108 b or to an inflatable tissue support. As illustrated in FIG.62, the single element strut 218 may also be configured from a materialsuch as a metal or polymer and with a design that permits flexibilityalong its length. Thus, upon valve closure, as illustrated in FIG. 61,the strut 202 bends radially inwardly along its length to provide adistribution of the closure forces on the valve.

The tissue support 200 may extend in an axial direction such that theapex 206 or downstream end 216 is positioned approximately at the levelof the downstream support ring 108 a, as has been illustrated, forexample, in FIG. 58. Alternatively, referring to FIG. 19, the apex 206may be positioned in between the upstream support ring 108 b and thedownstream support ring 108 a. As with FIG. 58, FIGS. 63, 64 and 64Ahave been simplified by omitting inflatable elements, fabric sleeves orother structure for associating the upstream and downstream supportrings. In this embodiment, the apex 206 may be positioned within therange of from about 0.5 cm to about 2.0 cm from upstream support ring108 b.

Alternatively, the apex 206 or downstream end 216 may be positioneddownstream from the downstream support ring 108 a, as illustrated inFIG. 63. The apex 206 may be positioned at least about 0.2 cm, and, incertain embodiments, between about 0.7 cm and about 1.0 cm downstream ofthe downstream support ring 108 a.

In any of the foregoing embodiments, the tissue support 200 may beconnected with respect to the downstream support ring 108 a in any of avariety of ways, such as through the use of sutures, glue, welding, orother tethered structures. The connection between the tissue support 200and the downstream support ring 108 a may either be rigid, or permit adegree of radial flexibility as has been discussed.

In one implementation, the tissue support 200 is secured with respect tothe downstream support ring 108 a using a bioabsorbable suture oradhesive, which will maintain the structural orientation of the valveduring implantation, inflation and curing of the inflation media. Aftera period of from about a few hours to 2 or 3 or more days, dependingupon the inflation media and the suture materials, the connectionbetween the tissue support 200 and the downstream support ring 108 awould dissipate, allowing the tissue support 200 to move radiallythroughout its predetermined range of motion.

In any of the foregoing embodiments, the geometry of the tissue support200 may take any of a variety of forms, depending upon the desiredperformance characteristics. For example, although illustrated in FIGS.58 and 63 as a circular cross section inflatable tube, the tissuesupport 200 may also be inflatable to a noncircular, such as an oval orelliptical configuration. This allows optimization of the minimumluminal diameter through the valve support, while maintaining thestructural integrity of the inflatable strut. The inflatable strut mayalso be a substantially constant cross section throughout its length, ormay change in cross section, such as by decreasing from a relativelylarge upstream cross section to a relatively smaller downstream crosssection. This may enable a distribution of bending forces, throughoutthe radial range of motion for the tissue support 200, as has beendiscussed. In the context of noninflatable tissue supports 200,circular, oval, elliptical, rectangular, or other cross sectionalconfigurations may be used, depending upon the desired performance.Rectangular (e.g. ribbon) cross sectional struts may be desirable forminimizing the wall thickness and maximizing MLD within the valvestructure. With noninflatable tissue supports 200, or tissue supportcomponents, any of a variety of progressively flexible designs may beutilized to distribute forces along the length of the tissue support200. This may include, for example, decreasing the cross sectional areaof the strut in a downstream direction, or increasing the density ofperforation, score lines, or other surface modifications or aperturepatterns to increase the flexibility in a downstream direction.

The cross sectional dimension of the 108 a and 108 b rings may measureabout 2.0 mm to about 4.0 mm in diameter but may also measure 1.0 mm indiameter where the apex inflation channels may measure about 0.7 mm toabout 3.0 mm in diameter but preferably about 2.0 mm in diameter. Withinthese inflation channels are also housed valving systems that allow forpressurization without leakage or passage of fluid in a singledirection. The two valves at each end of the inflation channel areutilized to fill and exchange fluids such as saline, contrast andinflation media. The length of this inflation channel 311 may varydepending upon the size of the device and the complexity of the geometrybut measures about 10 to 30 cm in length and has a diameter of about 2to 4 mm with a wall thickness of about 0.0002 to 0.010 inches. Theinflation channel material may be blown using heat and pressure frommaterials such as nylon, polyethylene, Pebax, polypropylene or othercommon materials that will maintain pressurization. The fluids that areintroduced are used to create the support structure where without themthe implant is an undefined fabric and tissue assembly. In oneembodiment the inflation channels 311 are filled with saline andcontrast for radiopaque visualization under fluoroscopy. This fluid isintroduced from the proximal end of the catheter with the aid of aninflation device such as an endoflator or other means to pressurizefluid in a controlled manner. This fluid is transferred from theproximal end of the catheter through two inflation tubes 306 which areconnected to the implant at the end of each inflation channel 311. Withreference to FIGS. 64A-68, in the illustrated embodiment, the inflationchannel 311 can have a valve 301 at each end whereby they can beseparated from the inflation tube 306 thus disconnecting the catheterfrom the implant. This connection can be a screw or threaded connection,a collecting system, an interference fit or other means of reliablesecurement between the two components. Under pressurization the twocomponents may be separated whereby the implant will remain pressurized.The pressure is maintained in the implant by the integral valve (i.e.,end valve) at each end of the inflation channel 311. In the illustratedembodiment, this valve has a ball 303 and seat to allow for fluid topass when connected and seal when disconnected. In between the ends ofthe inflation channel 311 is an additional directional valve 310 toallow fluid to pass in a single direction. This allows for the fillingof each end of the inflation channel 311 and displacement of fluid in asingle direction. Once inflated with saline and contrast this fluid canbe displaced by a fill media that solidifies from the proximal end ofthe catheter where the saline and contrast is pushed out one end of theinflation channel 311 and replaced with the new inflation media fluidand the inflation tubes 306 are then disconnected from the implant. Insome case the implant has one or more inflation tube 306 connections butit is preferred to have two inflation connections and a third or forthfor additional steering control. These (non-fluid) connections 307 mayuse the same attachment means such as a screw or threaded element butmay not have a fluid port since they are not used for communication withthe device and its filling.

The end valve system 301 consists of a tubular section 312 with a softseal 304 and spherical ball 303 to create a sealing mechanism 313. Thetubular section 312 is about 0.5 to 2 cm in length and has an outerdiameter of about 0.010 to 0.090 inches with a wall thickness of 0.005to 0.040 inches. The material may include a host of polymers such asnylon, polyethylene, Pebax, polypropylene or other common materials suchas stainless steel, Nitinol or other metallic materials used in medicaldevices. The soft seal material may be introduced as a liquid siliconeor other material where a curing occurs thus allowing for a through holeto be constructed by coring or blanking a central lumen through the sealmaterial. The soft seal 304 is adhered to the inner diameter of the wallof the tubular member 312 with a through hole for fluid flow. Thespherical ball 303 is allowed to move within the inner diameter of thetubular member 312 where it seats at one end sealing pressure within theinflation channels and is moved the other direction with theintroduction of the inflation tube 306 but not allowed to migrate toofar as a stop ring or ball stopper 305 retains the spherical ball 303from moving into the inflation channel 311. As the inflation tube 306 isscrewed into the inflation channel check valve (i.e., end valve) 301 thespherical ball 303 is moved into an open position to allow for fluidcommunication between the inflation channel 311 and the inflation tube306. When disconnected the ball 303 is allowed to move against the softseal 304 and halt any fluid communication external to the inflationchannel 311 leaving the implant pressurized. Additional embodiments mayutilize a spring mechanism to return the ball to a sealed position andother shapes of sealing devices may be used rather than a sphericalball. A duck-bill style sealing mechanism or flap valve wouldadditionally suffice to halt fluid leakage and provide a closed systemto the implant.

The various methods and techniques described above provide a number ofways to carry out the invention. Of course, it is to be understood thatnot necessarily all objectives or advantages described may be achievedin accordance with any particular embodiment described herein. Thus, forexample, those skilled in the art will recognize that the methods may beperformed in a manner that achieves or optimizes one advantage or groupof advantages as taught herein without necessarily achieving otherobjectives or advantages as may be taught or suggested herein.

Furthermore, the skilled artisan will recognize the interchangeabilityof various features from different embodiments disclosed herein.Similarly, the various features and steps discussed above, as well asother known equivalents for each such feature or step, can be mixed andmatched by one of ordinary skill in this art to perform methods inaccordance with principles described herein. Additionally, the methodswhich is described and illustrated herein is not limited to the exactsequence of acts described, nor is it necessarily limited to thepractice of all of the acts set forth. Other sequences of events oracts, or less than all of the events, or simultaneous occurrence of theevents, may be utilized in practicing the embodiments of the invention.

Although the invention has been disclosed in the context of certainembodiments and examples, it will be understood by those skilled in theart that the invention extends beyond the specifically disclosedembodiments to other alternative embodiments and/or uses and obviousmodifications and equivalents thereof. Accordingly, the invention is notintended to be limited by the specific disclosures of preferredembodiments herein

We claim:
 1. A method of implanting a prosthetic heart valve, the methodcomprising the steps of: translumenally advancing a catheter carrying aprosthetic valve that comprises an inflatable support structure to aposition proximate a native valve of a patient, wherein the inflatablesupport structure comprises at least two valves positioned at ends ofthe inflatable support structure; inflating a first chamber of theinflatable support structure with a contrast media wherein a directionalvalve is located between the at least two valves positioned at ends ofthe inflatable support structure, and wherein the directional valve isconfigured to inflate the first chamber in a first axial direction andto inhibit flow in a second axial direction opposite to the first axialdirection; visualizing the prosthetic valve under fluoroscopy;displacing the contrast media in the first chamber of the inflatablesupport structure with a new inflation media, and wherein thedirectional valve is configured to displace the contrast media in thefirst chamber with the new inflation media in the first axial directionand to inhibit flow in the second axial direction opposite to the firstaxial direction; and removing the catheter from the patient, leaving theprosthetic valve and the inflated first chamber of the inflatablesupport structure within the patient.
 2. The method of claim 1, furthercomprising allowing the new inflation media to solidify within the firstchamber of the inflatable support structure.
 3. The method of claim 1,further comprising proximally retracting the valve after the firstchamber is at least partially inflated.
 4. The method of implanting aprosthetic valve as in claim 1, additionally comprising the step ofremoving the native valve prior to the removing the catheter step.